Aarush Prakash

Posted on Feb 19

I Built a #1 App Store Developer Tool in Pure SwiftUI — Here's What I Learned

#swift #webdev #development #productivity

I got tired of jumping between browser tabs every time I needed
to format JSON, convert a color, test regex, or hash a string.
So I spent 6 months building a fix.

The result: Devly — a native macOS menu bar app with 50+
developer utilities. It just hit #1 in Developer Tools on the
App Store.

The Problem I Was Solving

Every developer knows the pain. You need to:

Quickly format some JSON
Convert a hex color to RGB
Test a regex pattern
Decode a Base64 string
Generate a UUID

So you open a browser tab. Then another. Then another.
Context switching kills your flow.

What I Built

Devly sits in your macOS menu bar. One click gets you instant
access to 50+ tools:

Encoding: Base64, URL, HTML, JWT, Unicode, Morse, ROT13
Hashing: MD5, SHA-256/384/512, HMAC, bcrypt, UUID generator
Formats: JSON, YAML, XML, CSV, SQL, TOML
Web Dev: Color converter, CSS/JS minifier, Markdown preview
Text: Regex tester, diff tool, case converter, timestamp converter

The Technical Challenges

1. Apple's App Sandbox

The biggest hurdle was getting all 50+ tools to work within
Apple's strict sandbox rules. Every tool that processes data
locally has to comply — retrofitting this late in development
was painful. Lesson: plan for sandbox compliance from day one.

2. Keeping the UI Truly Native

SwiftUI on macOS is still maturing. Getting the menu bar
popover to feel truly native — proper sizing, smooth
transitions, correct macOS conventions — required constant
referencing of Apple's Human Interface Guidelines.

3. Managing State Across 50+ Tools

I used a ToolProtocol pattern that each tool conforms to:

protocol ToolProtocol {
    var id: String { get }
    var name: String { get }
    var category: ToolCategory { get }
    func process(input: String) -> String
}

This kept everything consistent and made adding new tools
much faster.

4. Discoverability

With 50+ tools, finding the right one fast became a UX problem.
I built a custom SearchService that indexes tools by name,
category, and keywords.

What I'd Do Differently

Plan for sandbox compliance from day one
Build the ToolProtocol pattern earlier
Study the macOS HIG before writing any UI code
Test SwiftUI popovers on macOS early — they're quirky

The Result

6 months of nights and weekends. #1 in Developer Tools on
the App Store. Pure SwiftUI, fully
sandboxed, $4.99 one-time.

App Store

Website
All 50+ tools

What challenges have you hit building native macOS apps
in SwiftUI? Would love to hear in the comments!

DEV Community