Now that summer is nearing an end, I wanted to share a bit about a product I’ve been working on. I’m not entirely sure what it is yet, so I’m calling it a productivity app. It’s called Solarday. I started building it at the end of July, inspired partly by being fed up with todo list apps that were either too ugly and complex or too limited and wanting to see a macro- and micro-view of my day without drowning in an inbox littered with tasks.
I also wanted to use this opportunity to let Claude Code do most of the engineering while I focused on design. I’ve been a Cursor user for over a year and a Warp user for over 2 years, both powered by Anthropic and OpenAI models. I wanted to see whether I can add Anthropic’s much-loved terminal-based coding agent to my box of go-to tools. This required an immersive test drive in a real-world scenario. While that’s a post for another day, Claude Code certainly sped everything up. With Claude Code at my disposal and 37 Signals’ Shape Up methodology of building products, I was able to get Solarday to a public TestFlight in under 2 weeks of part-time building — a solid outcome.
A public TestFlight for an iOS app means that the app has to do what it says it can do — to be fully functional, private, secure, reliable and follow Apple’s Human Interface Guidelines so that it can be approved by real testers in Apple’s Beta App Review team. I’ve shipped full-featured native iOS apps to a public TestFlight before in similar timeframes well before LLM-driven coding dawned upon us, but it always required a lot more effort and basically full-time work in those quick sprints. This time, Claude Code took care of the engineering heavy lifting, while I was able to spend substantial time doing design iterations — the part I enjoy the most.
Now, as Apple gears up to launch its new phones next week, I’m gearing up to launch Solarday on the App Store. After 3 weeks in TestFlight, I’ve gathered the feedback I need to do one more round of design work to truly make Solarday a useful piece of software that helps you go about your day thoughtfully and get stuff done. With a Liquid Glass-first design and iOS 26 a few days away, I’m excited to finally share this product more widely with the world this month.
I’ve paused new TestFlight signups until the next build with a major design overhaul is ready. But if you visit solarday.app and join the list, I’ll send you a link as soon as it’s live.