Location-based alarm: it rings when you get close to your stop. For people who ride the bus, subway or train and are afraid of dozing off and missing their stop. You pick where you get off on the map and can rest on the way — the alarm rings with the screen locked, with no account or sign-up, and the data stays on the phone. Solo project, from spec to release build.
Background reliability without draining the battery.
Native Android and iOS app built with React Native. The person picks the destination on the map or searches for an address, sets the radius (50 m to 1 km) and puts the phone away: tracking runs in a foreground service with the screen locked and, when they get close, the alarm rings with sound, vibration and a full-screen alert, with a snooze option. Alarms can be one-off or recurring on chosen weekdays, and limited to a time window. To save battery, GPS accuracy only ramps up near the destination, and monitoring pauses outside the window and resumes on its own a few minutes before it starts. A native module handles the alarm sound, exact wake-ups and resuming after the device reboots. No account and no server: alarms and location stay on the phone, in encrypted storage. Built with spec-driven development (Spec Kit), one spec per feature.