Launch HN: Bitrig (YC S25) – Build Swift apps on your iPhone
Bitrig lets you create native Swift apps for your phone, on your phone, just by chatting with AI. It’s like Lovable for iPhone apps.
Here's a video of Bitrig in action: https://youtu.be/CUlWhF3ERME
We created SwiftUI at Apple to help developers make better apps with less code. Bitrig lets anyone build at this level of polish. If you've thought about making an iPhone app, Bitrig is the easiest possible way to get started with Swift.
Bitrig uses Claude Sonnet 4.0 with a simple system prompt and tool definitions to generate native Swift code. Normally running this on an iPhone would require compiling and signing it with Xcode, and you can’t run Xcode on an iPhone. So we did something… creative. We wrote a custom Swift interpreter! Among other things this lets you instantly preview your app in Bitrig and share it with just a URL.
If you have a paid Apple developer account, you can connect it with Bitrig. We’ll compile your app on our server and upload it to App Store Connect, so you can distribute it on TestFlight or the App Store. This last step also gives you a fully optimized build of your app that you can install right on your Home Screen.
We think there’s something electric about building apps directly on your phone. We hope you give Bitrig a try!
We’re ingesting Apple’s SDK frameworks into Bitrig piece by piece. If you try to build something and hit a missing framework, let us know and we’ll prioritize adding it.
Download Bitrig on the App Store: https://apps.apple.com/us/app/bitrig/id6747835910
Keep crushing!
For the most part, I think the look and feel of the apps benefits from SwiftUI baking Apple's design system into the defaults so heavily.
Also, side note: magic link or email-based OTP login is by far my least favorite method of login, especially for a phone app. It's cumbersome, annoying, and completely unnecessary now that passkeys exist. Barring that I'd still rather use email/pw login any day of the week.
We've definitely been hearing from users who don't like OTP, we'll try to get additional login options added soon.
I don’t pipe up very often, but I visit HN almost every day. Many of the books I read, blogs I frequent, and podcasts I listen to, I found via HN. I think it’s fair to say, if it weren’t for HN, that Bitrig wouldn’t be Bitrig and SwiftUI wouldn’t be SwiftUI.
In the meantime, one thing that's worked well for us is building a component/screen/etc as a standalone piece in bitrig, and then bringing it into a larger project from your computer later. You can easily export the code you make in bitrig for those kinds of workflows.
Are you imagining you'd be editing the code with the software keyboard or a paired hardware keyboard?
Really large and complex apps will probably require improvements to both Bitrig and the underlying models. However, both those are coming :)