For the past few weeks I've been building a shared grocery list app, native on both iPhone (SwiftUI) and Android (Jetpack Compose), with a small Next.js backend. I wrote very little of the code myself: I mostly steered AI coding agents (Claude Code), one per platform, running in parallel.
What worked
Writing a short spec and a shared API contract before any code. Both agents build against the same contract, so the apps behave the same.
Asking every agent for screenshots from a real simulator or emulator, not just "tests pass".
Snapshot tests and strict CI as the safety net: they catch the "small" visual regressions agents love to make.
A shopping list for the whole household. Whether you live as a couple, with family, or with housemates, everyone can add what’s needed, and everyone sees the same list—in real time. When you’re at the store and add an item to your cart, the others know immediately that it’s been picked up, and by whom.
