Building Sokesa
Sokesa is a training app for iPhone and Android: six timer formats, weekly progress, a photo journal with a before/after film, food planning, widgets and lock-screen Live Activities. I designed and built it on my own during the summer of 2026, as a product, from the first sketch to the store.
The problem
My training lived in five apps: one for intervals, one for weights, one for photos, notes for meals, and nothing tied them together. I wanted one place that made showing up again tomorrow the easy choice.
How I worked
- Interactive prototypes first. Every feature started as a clickable HTML mock-up with several options side by side. I chose, then turned the choice into a precise implementation brief.
- Small batches. The app grew through numbered batches (V5-01 to V5-59), each with a clear scope, a review and a commit.
- AI pair-programming. I wrote the briefs and made the product decisions; an AI coding agent wrote most of the code under that direction. I reviewed every batch on device, by screenshot and screen recording.
- Proof, not hope. Each batch adds automated checks, and a mutation “sabotage bench” breaks the code on purpose to prove the checks can fail.
In numbers
- 68 automated test suites, more than 10,000 checks run before every commit.
- Up to 86 deliberate mutations per batch, all caught.
- 6 timer formats, 5 themes, 6 accent colors, 4 widget types plus Quick start.
Technology
Expo SDK 54, React Native 0.81, TypeScript, Reanimated (animations on the UI thread), react-native-svg, expo-sqlite, native Swift modules (photo storage, contour detection), WidgetKit and ActivityKit, EAS Build.
Hard parts
- Performance. Screens that drew twice, wheels that mounted 500 views: measured, then rebuilt so every screen appears in one frame.
- Design system. One accent in both modes, five themes with contrast checked automatically (4.5:1 for text).
- Storage. Photos in private storage, mirrored into the Files app with hard links (0 MB extra), never deleted from Photos by mistake.
Links
App Store and Google Play: coming soon · Instagram · TikTok · YouTube