Launch HN: Bitrig (YC S25) – Build Swift apps on your iPhone

On a personal note, I wanted to thank the HN community. I’ve been reading HN since college (for over 15 years now!) and it’s been formative in my development as a software engineer and leader.

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.

Very cool! Was it difficult to get Bitrig approved on the App Store? If I had to guess just based on the idea, it seems like the sort of thing Apple would take issue with.

Neat. I just tried it out and one thing I was pleasantly surprised about was the styling it came up with. It was sleek, and it did not have the purply gradienty tailwindy styling that I always get from Claude. Did you do much to adjust the prompt for custom styles?

Seems like a cool concept! I downloaded and entered an email address but haven't received a verification code yet after 10 minutes. It's an Apple Private Relay email if that matters.

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.

So I have an existing typescript project, can I still use your software to build the app part of it in a monorepo?

This is a really good idea, but I’ve noticed that, even with developer experience and using Claude code, building a complex app is extremely difficult and takes dozens of prompts to get things actually working. This is probably a great prototyping tool, but I’m curious to know how far this can go to build production level apps.

Are there iOS apps that let me create native Swift apps for my phone (including execution on my device, not in the cloud), on my phone, but _without_ chatting to AI? Just by writing code, the "old" way?

I’ve just tested it out, and purchased a subscription within 5 minutes, for an app we were seriously discussing with a friend over the last days.

Keep crushing!

[dead]

Not to be confused with Bitwig music production studio/software.

I downloaded the app but it keeps crashing on open

I’ve been playing with the TestFlight build and it’s really solid. Can you share any under the hood details of how the system is able to accurately map the loose prompt to fully native SwiftUI components. Mostly curious because I’d love to also build internal data dense apps typically better suited for desktop.

Great work and I hope to become a paying customer soon!

I'm on an iPhone SE, and the UI doesn't quite fit. The response text isn't easily scrollable, so I have to drag the text up, instead of just scrolling.

this is super super cool - awesome to see something technically hard and novel. congrats on the launch!

Hey Kyle, looks very cool!

- If Bitrig can do things like let your app have editable data, or make rest api calls, etc. it would be nice to see a little more in the demo video.

- Sounds like you don’t have an expensive mic/studio for recording, but luckily this is free and can work wonders for your audio: https://podcast.adobe.com/en/enhance

Best of luck with the launch.

Doesn’t work at all for me.

Entered my my prompt… It did a bunch of stuff - apparently initially focused on making me an app icon which I don’t really care about.

I moved away from the app, went back and everything had gone and my prompt was just sitting there by itself.

I said “please proceed” and it opened a new chat, did the same thing. It was doing stuff, I moved to something else, went back, everything vanished.

So that’s two of my five free messages zapped. And all of my patience.

First, as a non-developer geek -- super fun.

What happens if you go over 100 messages/month?

I just burned my 5 free messages to get a simple toggle button working that just says "win" (with animated fireworks!) and "lose". I'm sure I'm not an efficient prompter, but it seems I'd knock out 100 messages easily in an afternoon, which looks to be the monthly limit at $20/mo.

(This is coming from someone who has no idea how expensive it would be to 'vibe code' using something like Claude ... so it may be an entirely unfair assumption that you could chat with this 'unlimited' for $20/mo ... that's what I have in my head as 'reasonable' only because that's what I pay for Gemini or ChatGPT and, for all intents and purposes, it feels 'unlimited'.)

It doesn't seem like this is the direction you are going, but this feels like what Siri could become (though I have little faith given the history).

With your sunscreen example, I should be able to just ask Siri to do exactly this, and it could tap me in my pocket, show me a custom UI to log periodically and then disappear.

Not sure on limitations of APIs on iOS but definitely feels like there is space for a better voice assistant, just like how Raycast have created a better Spotlight on Mac.

Looks very cool so far!

I love what you guys are doing but highlights how absurdly hard iOS development is compared to web

I wish Apple would let us build and install these apps locally without fuss.

I'm using Firefox for Android, and I'm unable to scroll on the homepage at all.

This app is really quite fascinating as well as amazing. I have been using it for a week now. I do like how it is so good with Swift and iOS; you have done a great job of removing so much of the confusion that LLMs must face when trying to develop for a demanding platform. The API insight the app has is a testament to your deep background and foresight into iOS development. I really love this.

Also, I have been taking the code and advice from Bitrig into Cursor, because it solves problems Cursor struggles with no matter what model it calls.

Your work is empowering, but more than that, it is inspiring, because I can now start to envisage what computer human interaction will look like in the near future.

You have taken away a layer of complexity to creation and that is to be applauded. I think your work is a landmark. I think Bitrig will unleash a new era of creative expression. I wish that I was part of your team.

Tried to create a canvas like app view, your app froze after some prompts (guess the swift interpreter?) reopening the app and selecting the project again does not help

I stopped using Apple products but need to create a couple of iOS apps. I was debating buying a Mac Mini or using "Macincloud" but this seems like an excellent option. Being able to edit the Swift code means fixing nuances.

I'll likely subscribe to your service.

For distribution strategy you could experiment with letting people create simple apps for free and put a perpetual ad for your service ad the bottom of the app.