I'm making an app to help manage personal finances, Ask Me Anything!

twitter logo github logo ・1 min read

As I've posted before, I'm building an app to help me convert a spreadsheet that I've managed to a multi-platform app. I'm flirting with the idea of making it open-source because I believe money is one of those things that we all wrestle with and can totally automate.

Ask me anything!

twitter logo DISCUSS (35)
markdown guide

we use gnucash to manage house accounting/budgets and there is a companion GnuCash for android to manage our wallet expenses, we can export the data from the mobile app, and import it to GnuCash desktop app to update our expenses.


Yeah, I've seen many apps like that. The only thing with some open-source apps out there is that they aren't too easy on the eyes. Maybe I'm crazy, but my vision is an app with a simple, clean design.


Future release. :) Also, I'm a veteran and use USAA (who is super secure and doesn't always let people import transaction history). So, Mint was never an option for me.

The idea is allowing your transactions to be predictable. I'm more of a hands-on type of guy, but ultimately the goal is to start predicting future balance based off of past history.

Mint can only tell you what's already happened. I'm wanting to predict what will likely happen. For example, if you frequent Starbucks, most apps will tell you that you spend a certain percentage on Starbucks.

If you typically get a coffee on Mondays, the app should be able to account for it based off of past history and say "hey, you usually buy a coffee on Monday, I'll add an entry for $5 so it's automatically budgeted"

AFAIK, I've not seen many apps that do that. Ultimately, that's the goal long-term. Short term is to account for stuff we already know like Rent and static bills.

I would love to also incorporate an automated amortization chart which would calculate your current credit cards, loans, etc and by using the history of your income and other bills, help you pay off debt faster by adding a little extra to your payments.


The personal project I am working on right now is similar. It's a multi-platform app to help manage personal finances that I thought of making open-source too.
I've always loved personal finances app, but for some reason I always quit using the apps. And I found out the reason is that I just can see the past of my finances, but not the future. And what I really wanted to see, is the future.
My approach is: If I get paid the same days in a month, on average the same amount and set up all the recurring expenses that I have, how much would I have in 4 months? Or any date in the future, say, next week. The idea sounds simple so the design I want it to be simple as well.

If you make it open-source, I'd rather collaborate in this project than making it by my own.
Let us know when you do it.


You hit the nail on the head, too. Sure, past finances help, but forecasting allows you to plan for stuff better.

If you know that in 3 months you'll have an extra $1000 bucks in your bank account, that's money that's not doing anything!

So many budgeting apps don't tell you about your money's potential and are very passive in the approach. I, on the other hand, want to know where I'm spending my money and make tweaks that give me more control. That's the idea behind Jelly Fin.

By tracking the minimum balance based off of historical values, I can forecast as long as I want and that way I can budget better.

My stretch goal for this is to predict values that change more dramatically using different algorithms. Chances are, some bills naturally go up in the extreme months like Summer and Winter. I want to predict those using a statistics term called Seasonality. Wouldn't it be neat to predict your Electric bill going up 40% and already planning for it?


I have made it open source! Check it out.

It's really in its infancy, but I'm trying to get it stood up quickly.

jonathan-irvin / jelly-fin

A simple way to manage your finances with forecasting. We should automate our money, not make it automate us.

Jelly Fin

Finances are hard. It's one of the first adulting things everyone has to wrestle with. So, let's make it easy and automate it. Over the course of several years, my wife and I have tracked our finances using a forecasting method and had done it all within a spreadsheet. The time came where I wanted to take this concept and make it mobile using serverless architecture and clean design.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.


For the API:

  1. Install NVM and download Node v6.x.x. LTS
  2. Install and configure ClaudiaJS


  1. Clone the repo.
  2. Run npm install to cover any dependencies.
  3. Run npm run claudia:create to install backend into AWS.

Running the tests

We don't have…


Great! I cloned the repository and I'm looking around. What do you wanna use for the front-end?

At this stage, probably React with Material Design, but I think we need to build out the backend first. There's a lot of ground work to be had with the build and deploy process, too. Right now, it's only using my AWS credentials, so stuff like that needs to be ironed out as well. So much to do!

Alright, I'll ask for a free trial on AWS Lambda and I'll learn what I have to to help out with the back-end.
And regarding the front-end: Are you thinking of developing a web app, mobile app or both?
In any case, I'm on fire with React and React Native so surely I'll be more helpful when we're on that.

It'd be good if we had a place to communicate and discuss about the project, where can we do it?

Best regards!


I would be interested in how you are modelling the data. Started doing something similiar and was in between a few strategies for a long time. In the end, I still stick to YNAB (youneedabudget.com/) but code on my own solution on the side.


Trying to keep it simple for now. Simple, as in only stuff like date, amount, transaction type, payee. My spreadsheet is simple, so I want my app for follow the same philosophy.


I think open sourcing it would be a great idea.

Can you give me the short overview of how the app works?


Over several years I've tweaked a spreadsheet. My wife and I budget by forecasting. The goal is to make that forecast more accurate by applying seasonality statistics to variable costs...like an electric bill. Everything else that stays the same would be a constant and can easily be used.

We look at our finances like what is the minimum amount in our bank account on any given month and move money around based on that.

I'm using this app to learn Serverless architecture and use my front end developer experience to make it pretty.


I love that you've established the tag on-site and are walking folks through the journey. I think if you make it opensource, it could be a really strong lasting project. I'd immediately start looking for ways to contribute.

Ok, you've convinced me. I'm going to do it. I'm going to make this open-source. I guess I need to make the repo public, outline all of the features and notes I've taken and put them in GitHub issues to track features, then just attack it KanBan style.

If people join in, sweet. If they don't, then at least I got organized.


Would love to contribute, as I'm starting to wrangle my finances!

Is the app currently live or is it meant to run as an offline app?


It's still in development, so you can get in early! I want to work on the backend first, then the front end.

I'm not interested in having this make money. May take a patreon or something like that later, but ultimately want it running so I can use it. :)


Adding to that, I'd want it to be synced to the cloud for convenience (which is how I'm working on it now).

Awesome, not 100% familiar with the stack but I'll take a look. :)

And I'm not 100% set on my stack, but open to ideas!


What is different from the existing finance management apps?


I don't want it to be complicated. 😉


I believe there are apps where you just insert an amount of money and then split it for different purposes. That sounds simple enough.

What do you have in mind? Is your concept uploaded somewhere? GitHub maybe?

edit Nevermind, I checked your next posts!


Backend, I'm thinking Serverless. I'm going to try Firebase for this. Frontend would be React Native.


What technologies/languages do you have in mind for it?


Serverless for the back end using AWS and dynamodb. Thinking React for the front end. Needs to work on Android and iOS. So, Cordova? Not focusing on front end yet. I have to get my infrastructure down solid first.


how would you make it easy for users to actually input data? because that mundane part makes people not use apps like these.


At first, it may feel like a grind. Imagine doing it all in Excel! The grind is what made me want to do this. The goal is to automate your finances and take the thought out of it.

I'm not really interested in scanning bank accounts, although that would be a cool stretch goal.


I just did! I love the dev.to community. You guys are awesome. I've also been writing about it on here. Checkout the link above.


Does the app exactly serve all your financial management? or plan to use it as a day-to-day tool?

Cuz such apps eventually get into a non-rational big hard-to-use :(

Classic DEV Post from Jun 30 '19

What is your favourite Git command?

Jonathan Irvin profile image
I'm a full-stack cloud-minded engineer who enjoys devops and clean code.