r/SideProject•3 mo. ago

After building it solo, my on-device readiness-score app is live — no subscription, nothing leaves the phone

Most recovery apps hand you a number with no explanation, lock it behind a subscription, or make you buy their hardware. I wanted the opposite, so I built it.

Tawen reads the sleep, HRV and activity your phone already records through Health Connect, scores your day 0–100, and explains what drove it in plain English — generated on-device. No account, no cloud, no subscription. One-time $4.99 for the Pro extras; the free app is genuinely complete.

Honest tradeoffs from building solo: the on-device AI explanation only runs on recent flagships (older phones get a solid rule-based version with the same score), and it's US + Canada, Android 9+ at launch while I keep the compliance surface small.

The thing that surprised me most building solo: the on-device model (Gemini Nano) flat-out refuses to run in the background – it only generates while the app is actually on your screen. I spent a while fighting that before realizing it's the most honest version of "on-device" there is: the model literally can't run while you're not looking. So the explanation writes itself when you open the app, never behind your back.

Would value feedback on everything and anything. Happy to answer anything about the on-device side.

Tawen on Google Play

PROMO

Here are 25 redeem code for Pro, for our community, up for grabs on first come - first serve basis:

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