DEV Community: anoop p

What I Shipped in April Building Invoiso(v4.0.5)

anoop p — Sat, 02 May 2026 16:44:09 +0000

April was one of the busiest months so far while building Invoiso, a free offline invoice and billing tool for Windows and Linux.

This month was less about one big headline feature and more about making the app work better for real businesses: due dates, quotations, customer imports, product imports, bank details, better PDF downloads, and a lot of layout and reliability fixes.

All Changes Shipped in April 2026

GitHub · Website · Download

The Focus This Month

The focus for April was:

Better invoice follow-up with due dates and overdue visibility
Cleaner separation between invoices and quotations
More flexible payment details with UPI and bank accounts
Faster data entry through CSV import/export
Better support for service businesses and custom line items
More reliable PDFs, exports, and layouts

Multiple UPI Accounts

UPI support is now more flexible.

Instead of storing only one UPI ID, Invoiso now supports multiple UPI payment accounts in Settings.

Add multiple UPI accounts
Give each account a friendly label, like "HDFC Bank"
Mark one account as the default
Select the UPI account while creating an invoice
Print the selected UPI account QR code on the generated PDF

This is useful when a business accepts payments through different bank accounts or wants separate payment accounts for different invoice types.

Bank Account Details on Invoices

Along with UPI accounts, Invoiso now supports multiple bank accounts.

Each bank account can store:

Label
Bank name
Account number
IFSC code
Default account status

There is also a new Show Bank Details on Invoices setting. When enabled, the selected bank account is printed on generated PDFs across all three templates: Classic, Modern, and Minimal.

This makes invoices more complete for customers who prefer bank transfers instead of UPI payments.

Due Dates, Overdue Invoices, and Due Soon

Due date support was a big part of the April work.

Invoices now have an optional Due Date field next to the existing Order Date. The due date can be cleared after selection and is printed on PDFs across all templates.

The invoice list now shows both Order Date and Due Date in the date column. Unpaid overdue invoices are highlighted in red with an Overdue badge, and invoices due today are highlighted in amber with a Due Today badge.

There are also new due date filters:

All Dues
Overdue
Due Today
Due This Week
Due This Month

The dashboard also became more useful for follow-up work:

Due Soon shows unpaid or partial invoices due today or tomorrow
Overdue Invoices shows unpaid invoices past their due date
Quick actions are available for view, PDF preview, and record payment
Dashboard stats now show outstanding balance, collected revenue, overdue counts, and out-of-stock counts

This makes Invoiso better for day-to-day invoice tracking, not just invoice generation.

Separate Quotations Screen

Invoices and quotations now have separate screens.

There is a dedicated Quotations entry in the navigation rail, and quotation management has its own table. Since invoices and quotations are now separated, the old Type column was removed from both screens.

The quotations screen also hides payment-specific actions and columns:

Status column
Outstanding balance column
Apply payment button
Hide paid toggle
Due date filters

The screen title now changes based on context: Invoice Management or Quotation Management.

This makes quotation workflows much cleaner.

Customer Management Improvements

Customer management got a major upgrade with CSV import.

You can now bulk import customers from a CSV file using strict headers:

name, email, phone, address, business_name, tax_number

The import flow includes:

Import rules dialog
Downloadable sample CSV
200-row import limit
Duplicate detection by email or phone
Preview dialog for valid rows, duplicates, and errors
Per-row Skip / Overwrite controls
Overwrite All / Skip All shortcuts
BOM handling for Excel-saved CSV files

Customer CSV export was also updated to match the import format, with all fields double-quoted for better round-trip compatibility.

There is also an admin-only Delete All Customers action with a confirmation dialog.

Another important addition is Business Name. It now appears in the customer form, CSV import/export, invoice customer details, and generated PDFs below the customer name.

Save Customer While Creating an Invoice

The create invoice screen now lets you save customer details directly from the Customer Details card.

If the customer does not exist, they are added to the customer list without leaving the invoice screen.

If a customer with the same phone number already exists, Invoiso asks whether to update the existing record or keep it unchanged.

Once saved, the customer is automatically selected for the invoice and the button changes to Saved to prevent duplicates.

This removes one of the small but annoying context switches while creating invoices.

Product Management CSV Import / Export

Product management now supports CSV import and export too.

Products can be imported with these strict headers:

name, description, price, tax_rate, hsn_code, stock, type

The product import flow includes:

Import rules dialog
Downloadable sample CSV
500-row import limit
Duplicate detection by product name
Per-row Skip / Overwrite controls
Overwrite All / Skip All shortcuts
BOM handling for Excel compatibility

Products can also be exported to CSV, and selected products can be exported too.

There is also an admin-only Delete All Products action.

Product and Service Support

Products now have a Type field:

Product
Service

The type is displayed in the product list and carried through to invoice line items.

This also connects with invoice settings. Businesses can now decide how quantity should behave for their use case.

Show Quantity Toggle

There is a new Show Quantity toggle in Invoice Settings.

When disabled, the Qty column is hidden from the invoice item table on screen and from generated PDFs.

This is helpful for service businesses that bill by description or scope instead of quantity.

Fractional Quantities

Quantities can now support decimal values.

Examples:

1.5 hours
0.5 kg
2.25 units

There is a new Allow Fractional Quantities toggle in Invoice Settings. It is off by default, so businesses selling physical goods can keep the simpler whole-number flow.

When enabled, quantity inputs accept decimal values and display cleanly: whole numbers appear as 2, while fractional values appear only when needed.

Discount Per Unit

Line item discounts are now more flexible.

Each invoice item has a Discount per unit toggle.

When disabled, the discount is applied to the line total:

(price x quantity) - discount

When enabled, the discount is applied before multiplying:

(price - discount) x quantity

Existing invoices stay backward compatible and continue using the original behavior.

Additional Costs

Invoices now support additional invoice-level costs.

There is a collapsible Additional Costs section where you can add rows such as:

Shipping
Packaging
Handling

Additional costs are added after tax calculation and are shown separately in the invoice totals panel and generated PDFs.

Multiple cost rows are supported, and the section header shows a count badge when costs are added.

Custom Items and Price Overrides

Invoice line items are now much more flexible.

You can override the unit price for a product directly inside the add/edit item dialog. Overridden prices are highlighted in the invoice item list with an asterisk.

There is also a Custom Item button in the product search area. This lets you add one-off items without creating a product first.

Custom items support:

Custom name
Custom price
Custom tax rate when per-item tax mode is enabled
Persistence when editing invoices
Correct PDF and CSV export output

Custom items can also be saved back into the product catalogue directly from the invoice screen.

GST, Tax Labels, and Country Support

Invoiso now has better support for businesses that do not need GST fields.

There is a Show GST Fields toggle in Invoice Settings. When disabled:

GSTIN field is hidden from the invoice screen
GSTIN is excluded from exports and PDFs
HSN Code is hidden from generated PDFs
Tax row is hidden from PDFs
Enable Tax toggle is hidden and tax is automatically disabled

Company Info also now has a Country field with searchable autocomplete covering 195 countries. It defaults to India.

The tax label is dynamic:

India or blank country: GSTIN
Other countries: Tax/VAT No

This applies across the invoice form, all PDF templates, and payment receipts.

PDF View, Download, and Bulk Export

PDF handling improved a lot this month.

The PDF preview window now has Print and Download buttons in the toolbar. Download opens a file picker so the user can choose exactly where to save the PDF.

Downloaded files now use a clearer filename format:

inv-{number}-{customerfullname}-{date}.pdf

For example:

inv-42-john_doe-20260402.pdf

The download button is also available from:

Invoice list
Dashboard recent invoices
Create/edit invoice screen

Bulk PDF downloads also improved. Selecting multiple invoices and clicking Download PDFs now asks whether to:

Save PDFs to a folder
Save all PDFs as a ZIP

The ZIP option uses a filename like:

invoices_YYYYMMDD.zip

A progress dialog shows generation progress for both folder and ZIP export modes.

Company Info and Invoice Customization

Several invoice customization options were added or improved.

Company website now prints on PDFs when set
Company phone supports multiple numbers separated by commas
Phone input supports international formats with +, spaces, and parentheses
Country, phone, and email fields are grouped into a cleaner row in Company Info
Company logo size can be set to Small, Medium, or Large
Logo size applies to all PDF templates
Invoice details card is wider for better readability
Customer Details form was reorganized into two rows of three columns

The sidebar logo also improved: the expanded sidebar shows the full horizontal logo, while the collapsed sidebar shows the square app icon.

CSV Export Improvements

CSV export received several fixes and quality-of-life improvements.

Invoice CSV export is sorted by invoice number in ascending order
Export now opens a filter dialog before exporting
You can export all records or choose a date range
Validation prevents exporting when the To date is before the From date
Invoice screen exports only invoices
Quotation screen exports only quotations
CSV filenames and first-column headers now reflect invoice or quotation type
Due Date column is included
UPI/payment account column is included
UTF-8 BOM is added so Excel and LibreOffice read files correctly
Unicode multiplication symbol was replaced with plain x to avoid encoding issues

This makes exports more predictable and safer for spreadsheet usage.

Dashboard Improvements

The dashboard is becoming more operational.

New and improved sections include:

Total Revenue Collected
Outstanding Balance
Due Soon
Overdue Invoices
Out of Stock
Reports coming soon placeholder

The dashboard content is now capped at a cleaner max width and centered on large screens.

Layout and Shared Widget Work

April also included a lot of layout cleanup.

New layout width constants were added:

maxWidthNarrow = 900
maxWidthNormal = 1200
maxWidthWide = 1700

These are used across settings, dashboard, customer, product, invoice list, and create invoice screens to keep large displays readable.

The reusable CustomerInfoButton widget was also extracted and is now shared by the invoice list and dashboard Due Soon section.

Smaller Improvements

Other improvements shipped this month:

New Invoice shortcut appears in the AppBar while editing an invoice
Invoice number info card explains how invoice numbers are generated
Invoice number tooltip shows the same explanation on hover
Tax rate segment selector now has individual tooltips
PDF action tooltip renamed to PDF View / Download
South African Rand (ZAR) added to supported currencies
Product/service type label removed from generated PDFs
Error SnackBars now include a copy icon so error messages can be copied easily

Bug Fixes

This month also included many bug fixes.

Fixed Additional Notes not saving or displaying correctly
Fixed discount calculation issues in certain scenarios
Fixed New Invoice from edit mode not fully resetting the form
Fixed layout overflow in invoice and quotation customer columns
Fixed sparse invoice lists being vertically centered instead of top-aligned
Fixed Enable Tax toggle showing when GST fields were disabled
Fixed dashboard recent invoice layout issues
Fixed due date row overflow on smaller screens
Fixed invoice list date column overflow
Fixed invoice/quotation switching not reloading the correct data
Fixed UPI dropdown layout crash from unbounded width constraints
Fixed CSV garbled characters in Excel and LibreOffice
Fixed missing Due Date and UPI/payment account columns in CSV export
Fixed invoice totals row overflow on narrow screens
Fixed invoice type dropdown overflow
Fixed collapsed sidebar chevron overlapping the logo
Fixed discount per unit not persisting when editing invoices
Fixed Total Due disappearing from PDFs immediately after updating an invoice
Fixed invoice notes not appearing consistently on newly created invoices
Fixed Amount Paid and Amount Due row overflow
Fixed saving custom items to the product catalogue from the invoice screen
Fixed tax row printing on PDFs when GST fields were disabled
Fixed bulk PDF filenames using the old Invoice_00000001.pdf format
Fixed startup crash from duplicate DB migration columns
Fixed DB migration ordering for v16 through v20
Fixed PDF preview crash when bank details were included

Not glamorous work, but this is the kind of polish that makes the app feel more dependable.

What I Learned

Follow-up workflows matter.
Due dates, overdue indicators, and due-soon cards make the app more useful after an invoice is created.

Import/export needs to be strict.
CSV import sounds simple, but real-world files need validation, duplicate handling, sample files, row limits, and Excel compatibility.

Small layout bugs add up.
Many fixes this month were about overflow, width constraints, and screen-specific UI. These are easy to ignore during development but very visible to users.

Invoices and quotations deserve separate workflows.
Keeping them in one table worked for a while, but separating them made the product easier to understand.

What's Next?

Next, I am exploring:

Better reporting and analytics
More invoice customization
Better payment workflow improvements
More polish around import/export flows
Continued Linux and Windows desktop stability improvements

Feedback Welcome

If you have tried Invoiso or have any thoughts:

What workflow still feels slow?
What should be easier?
What feature would make Invoiso more useful for your business?

Add a comment below or open an issue on GitHub.

Invoiso is free, open source, and runs entirely offline. No account required. No data leaves your device.

Thanks for reading. More updates soon.

What I Shipped This Month Building Invoiso (v3.4.2)

anoop p — Tue, 31 Mar 2026 13:50:27 +0000

One of the best things about working on Invoiso, a free offline invoice and billing tool available for Windows and Linux operating systems, has been “building in public.” This month has been particularly fruitful as a mix of long-pending features, quality-of-life enhancements, and critical bug fixes were included.

All Changes in v3.4.2 👇

🔗 GitHub · Website · Download

💡 The Focus This Month

This release is all about:

More flexibility in invoicing
Better real-world usage
Smoother payments and workflows

🌍 Multi-Currency Support

One of the most requested features is finally here.

Create invoices in different currencies:

INR · USD · EUR · GBP · JPY · AED · SGD · AUD · CAD · JMD

Each invoice locks in the currency at creation time, maintaining historical data’s accuracy.

Why is multi-currency support important?
If you work with clients across borders, you know how annoying currency conversions can be.

🧾 Per Item Tax Rates

Tax rate is now set per item.

Tax rate is no longer set at the invoice level.

Why is per item tax rate useful?

Mixed GST items
Different tax rates for different service/product types

This makes things more similar to real-world usage.

💸 UPI QR Code on Invoices

A significant feature update for users in India.

Enter your UPI ID in settings
A QR code is automatically added on every invoice you create in PDF format

Clients can also scan and pay instantly using GPay, PhonePe, or Paytm. There is no need to type anything or get confused.

🔁 Invoice Cloning

Creating similar invoices was a tedious task. This feature lets you clone an invoice and use it as a starting point.

A small feature, a big time saver.

📦 Bulk Actions

You can select multiple invoices and perform actions on them in bulk.

More efficiency, less clicks.

💳 Payment Tracking & Receipts

This was a big feature.

Mark invoices as Paid / Partially Paid / Unpaid
Track payment history
Generate downloadable PDF payment receipts

This feature alone makes Invoiso not just an invoice generator, but a basic invoicing system.

🔐 Role-Based Access Control (RBAC)

This feature is for those who work in teams.

Set admin and user roles
Set access level for each user

This feature will pave the way for more user-based features.

🧭 Invoice Type Indicator

The invoice type is also visible on the invoice list and dashboard. There is no need to click on an invoice to know its type.

A small feature, a big time saver.

🖥️ Ubuntu 24.04 LTS Support

Linux users, rejoice! Builds are tested and working on Ubuntu 24.04 LTS.

🎨 UI/UX Improvements

Redesigned: PDF Settings, Company Info, and Software Info screens
Fixed: annoying bug where search fields lost focus on fast typing
General layout and visual polish on screens
Fixed ₹ symbol rendering incorrectly in generated PDFs
Fixed database connection dropping after backup restore
Fixed window resizing issues on Linux
Updated Windows app icon (all sizes: 16, 32, 48, 256px)

📊 What I Learned

Some observations and insights from this release cycle:

Small UX issues matter more than missing features.
The search field focus bug was reported most. More than any missing feature. Fixing UX issues is important.

Payments are core, not optional.
Tracking and receipts are a big part of any payment process. This is a game-changer for the product. Should have done this earlier.

Speed of iteration > perfection.
Shipping is important. Consistency is key. Will improve and iterate soon.

🔮 What's Next?

Exploring next for Invoiso:

Improving reporting & analytics
Improving payment workflows
Improving invoice customization options

🙌 Feedback Welcome

If you have tried Invoiso or have any thoughts on it:

How are you using Invoiso?
What is missing?
What is clunky?

Add a comment below or open an issue on GitHub. I read all of them.

Invoiso is free, open source, and runs entirely offline. No account required. No data leaves your device.

Thanks for reading! More updates soon! 🚀

I built a free Android soundboard that works with a External keyboard

anoop p — Wed, 25 Mar 2026 11:29:40 +0000

A few months ago I needed a simple soundboard for a live session. I wanted to trigger audio clips from a Bluetooth/External keyboard connected to my Android phone - just press a key, hear the sound, instantly.

Every app I found was either subscription-based, required an account, or didn't support physical keyboards at all. So I built CTunes.

What CTunes does

CTunes maps keyboard keys (A-Z and 0-9) to audio files on your device. Tap the on-screen button or press the physical key — the sound plays immediately.

That's the whole pitch. 36 keys. Any audio file. Zero lag.

Try it

I'd love feedback — especially from anyone who uses soundboards for live performance, streaming, or teaching. What features would make this more useful for your workflow?

Core features

Key mapping — pick any audio file from your device and assign it to a key
Dual input — works with on-screen taps and physical Bluetooth keyboards
18-color palette — each key gets a unique color so you can read the board at a glance
Import / Export — your entire layout serialises to a single JSON file
Persistent storage — mappings survive reboots and reinstalls via SQLite + takePersistableUriPermission()
Free — ad-supported, no subscription, no sign-in, works fully offline

The tech stack

CTunes is a native Android app written in Java (yes, Java — not Kotlin). Here's how the main pieces fit together:

Architecture

Single-module project, Activities only
No Fragments, no Navigation component
SQLite via a hand-rolled SQLiteOpenHelper
SharedPreferences for UI settings (grid size, column count, keyboard visibility)

Audio playback


java
// A new MediaPlayer is created per keypress
// The previous one is released first to avoid leaks
if (currentPlayer != null) {
    currentPlayer.release();
}
MediaPlayer mp = MediaPlayer.create(this, uri);
if (mp != null) {
    mp.setOnCompletionListener(MediaPlayer::release);
    mp.start();
    currentPlayer = mp;
}

I Built an Android App Because Android Kept Deleting My Clipboard

anoop p — Thu, 19 Mar 2026 04:52:06 +0000

Here's something that has happened to all of us.

You copy a link. Then you copy someone's phone number. You go to paste the link - and it's gone. Replaced by the phone number. Android only remembers the last thing you copied. That's it. One item. Always.

I kept running into this. Copying a piece of text, copying something else on top of it, then needing the first thing back with no way to get it. I'd go back to the original source, find it again, copy it again. Every time. It was a small annoyance, but it happened constantly.

So I built CopyDuo

What CopyDuo Does

CopyDuo runs quietly in the background and saves everything you copy - up to 50 items. Whenever you need something you copied earlier, you open the app, find it in the list, and tap it to copy it back to your clipboard.

That's it. No accounts. No cloud. No internet connection. Your clipboard history stays on your device, private and instant.

It also handles something I found genuinely annoying about other clipboard apps: duplicates. If you copy the same text twice, CopyDuo stores it only once. Your history stays clean.

Why This Problem Is Harder to Solve Than It Looks

When I started building this, I thought it would be straightforward - just listen for clipboard changes and save them to a local database. Simple, right?

Not quite.

Android 12 Made Background Services Much Harder

To capture clipboard items when the app isn't open, I needed a background service - a piece of code that keeps running even when you're not actively using the app. On older Android versions, this was manageable.

On Android 12 and above, Google introduced strict restrictions on background services. Apps can no longer just run freely in the background. There are limits on when a service can start, and if you don't handle it correctly, the system kills your service entirely - meaning you miss clipboard items.

Getting this right took significant work. CopyDuo uses a foreground service (the kind Android officially supports for long-running tasks) with a persistent notification. This keeps the service alive reliably without fighting the system - and without draining your battery.

On New Devices, Apps Can't Read Your Clipboard in the Background

This one genuinely surprised me.

Starting with Android 10, Google added a privacy restriction: apps can only read clipboard data when they are actively in use - meaning they're the foreground app the user is currently interacting with. A background service can't silently read your clipboard anymore.

This is actually a good privacy decision. You don't want random apps reading everything you copy in the background. But it created a real problem for a clipboard manager.

I had to find another way.

The solution: a button in the notification panel.

When CopyDuo is running, it shows a persistent notification. That notification has a "SAVE TEXT" button. When you tap it, the app briefly comes to the foreground, reads your current clipboard content, saves it, and steps back. It's a one-tap action that takes less than a second.

It's not the invisible magic I originally wanted, but it works reliably on every Android version - including the latest ones - without any workarounds that could break with future updates.

What It Looks Like in Practice

Your day-to-day usage looks like this:

You copy something → CopyDuo saves it automatically (on older devices) or you tap the notification button (on newer devices)
You copy something else on top of it → no problem, both are saved
Ten minutes later you need the first thing → open CopyDuo, tap it, done

The list shows your most recent 50 items. You can delete individual ones or clear everything at once.

Another Way to Save: the Text Selection Menu

While working around the Android 10+ clipboard restriction, I found another clean solution that fits even more naturally into how people actually use their phones.

When you long-press any text in any app — a browser, a PDF reader, a messaging app — Android shows a floating toolbar with options like Copy, Cut, and Share. CopyDuo adds its own button to that menu: "Save to CopyDuo".

Select any text → tap Save to CopyDuo → it's in your history. No need to copy first. No need to open the notification. No steps in between.

This works everywhere Android shows the text selection menu. Reading an article and want to save a quote? Select it, tap Save to CopyDuo. Found a useful command in a tutorial? Same flow.

Between the notification button and the text selection action, CopyDuo covers every scenario — whether you're copy-pasting quickly or deliberately saving something you just read.

Why I Kept It Offline

A lot of productivity apps want your data in the cloud. Sync across devices, access from anywhere - it sounds convenient.

But your clipboard is where passwords live. Phone numbers. Bank account details. Private messages. One-time codes. The idea of that data leaving your device and sitting on someone's server made me uncomfortable - and I figured it would make you uncomfortable too.

CopyDuo has no internet permission. It physically cannot send your data anywhere. Everything is stored locally using a lightweight on-device database, and it never leaves your phone.

Download CopyDuo

It's free on the Google Play Store.

Get CopyDuo on Google Play →

Works on Android 8.0 and above. No account required. No subscription.

If you've ever lost something you copied, give it a try. It solves exactly one problem - but it solves it well.

I Built a Free, Offline Invoice App with Flutter - No Cloud, No Subscription, No BS

anoop p — Thu, 12 Mar 2026 15:48:17 +0000

Every time I needed to invoice a client, I ran into the same wall: every decent invoice tool either locks your data in the cloud, wants a monthly subscription, or both. I just wanted something that works offline, keeps my data on my machine, and doesn't cost me anything.

So I built it.

Invoiso is a free, open-source desktop invoice app for Windows and Linux. No account. No internet. No recurring fee. Just a binary you run on your machine.

Why Flutter for a Desktop App?

Flutter is usually talked about in the context of mobile. But Flutter's desktop support has matured a lot - and it gave me a few things I really wanted:

One codebase for Windows and Linux - I didn't want to maintain separate projects.
A rich widget ecosystem - building forms, data tables, and PDF previews is fast.
Dart's type safety - for a data-heavy app with models, migrations, and services, it helps.

The build output is a native binary - no Electron, no Chromium, no 300 MB runtime. The Linux AppImage is lean and starts instantly.

The Stack

Layer	Tech
Framework	Flutter 3.x (Dart)
Database	SQLite via `sqflite` + `sqflite_common_ffi`
State Management	Riverpod
PDF Generation	`pdf` + `printing`
QR Codes	`qr`
CSV Export	`csv`
Window Management	`window_manager`
File Picker	`file_picker`

SQLite with sqflite_common_ffi is the key piece for desktop. The mobile sqflite package doesn't work on Linux/Windows - sqflite_common_ffi wraps the native SQLite library and exposes the same API, so the transition is seamless. All data lives in a single .db file the user controls.

Project Structure

lib/
├── main.dart
├── common.dart          # Shared enums and data classes
├── constants.dart       # UI constants
├── database/            # SQLite helpers and CRUD services
├── models/              # Invoice, Customer, Product, ...
├── providers/           # Riverpod state providers
├── screens/             # All UI screens
├── services/            # PDF generation, CSV/PDF export
├── backup/              # Backup and restore logic
└── utils/               # Logger, formatters, error handler

The database layer follows a service pattern - each entity (invoices, customers, products) has its own service class wrapping raw SQL. Migrations are handled manually in database_helper.dart with a version counter.

Interesting Technical Bits

1. PDF Generation with Three Templates

PDF output is generated using the pdf package (not a web renderer - actual vector PDF). I built three templates: Classic, Modern, and Minimal - each with a distinct layout and color scheme.

The tricky part was making the layout adaptive to variable-length item lists, long product descriptions, and optional sections (GST, UPI QR, logo). The pdf package has its own layout model (similar to Flutter widgets but without hot reload - so a lot of trial and error).

2. UPI Payment QR Code on Invoices

For Indian users, I added UPI QR code embedding. When a UPI ID is configured in settings, the PDF generation encodes a upi://pay?pa={upi_id}&am={total} URI into a QR code using the qr package and renders it directly in the PDF footer. Clients can scan it with GPay, PhonePe, or Paytm to pay instantly.

3. Multi-Currency with Per-Invoice Snapshots

Currency is selected globally in settings, but each invoice stores its own currency_code and currency_symbol at creation time. This means if you change your default currency later, old invoices still display correctly. A simple but important detail - got it wrong the first time and had to add a DB migration.

Speaking of migrations: I maintain a DB_VERSION constant and a chain of _upgradeDbV{n} functions. Each upgrade is additive (new columns with defaults, new tables) - no destructive changes.

4. Backup and Restore

The backup feature is a plain file copy of the SQLite .db file to a user-chosen directory. Restore reverses it. Simple, robust, and the user owns the backup file - they can put it on a USB drive, copy it to another machine, or commit it to their own repo.

Features at a Glance

PDF invoices - one-click generation in Classic, Modern, or Minimal templates
Invoices and Quotations - with color-coded tracking
Invoice cloning - duplicate any document with one click
Bulk actions - multi-select to export CSV, generate PDFs, or delete
UPI QR code - embedded scannable payment QR in every PDF
GST ready - GSTIN fields, HSN codes, per-item or global tax rate
Multi-currency - INR, USD, EUR, GBP, JPY, AED, SGD, AUD, CAD, JMD
Customer and product management - full CRUD with search and pagination
Soft delete / Trash - recoverable deleted invoices
CSV export - for spreadsheets or accounting software
Backup and restore - one-click, local file
Security - login with brute-force protection and session timeout
100% offline - zero network calls, ever

Download

Platform	Format
Windows	`.exe` installer
Linux	`.AppImage` (portable)
Linux	`.deb` package

Grab the latest from the Download page.

Build from Source

git clone https://github.com/Anooppandikashala/invoiso.git
cd invoiso
flutter pub get

# Run in debug mode
flutter run -d linux    # or -d windows

# Release build
flutter build linux --release
flutter build windows --release

Prerequisites: Flutter SDK >= 3.3.3. On Linux you'll also need clang, cmake, ninja-build, and libgtk-3-dev.

What's Next

There's a solid list of planned features:

Invoice status tracking (Paid / Unpaid / Overdue / Draft) - the biggest gap right now
Due dates and payment terms (Net 7, Net 30, etc.)
Payment recording with partial payment support
Recurring invoices for retainers and subscriptions
Revenue reports with date range filters
Dark mode
Global search across invoices, customers, and products
GST report export in GSTR-1 compatible format (for Indian users)

If any of these interests you, contributions are welcome.

Contributing

Fork the repo
Create a branch: git checkout -b feature/your-feature
Open a pull request

Bug reports and feature requests go in GitHub Issues.

The whole thing is MIT licensed. If it saves you time or money, great - that's the point. If you want to help make it better, even better.

GitHub: github.com/Anooppandikashala/invoiso
Website: invoiso.co.in/