Monster Tag
Kids' peek-a-scare timing game for ages 6-12: collect monsters, build loadouts, and pull off the perfect scare. React Native + Expo with a server-authoritative Spring Boot backend.
Your monsters hide around a sleeping kid's bedroom: the closet, the window, under the bed. Tap them as they pop out to fill the Scare Meter before time runs out, but freeze when the parent's flashlight comes on. Open packs to collect 62 monsters with rarity and stats, build a loadout of tools, and earn stars to unlock 20 bedrooms.
Fully playable offline as a guest; signing in makes the server authoritative. The backend is Java 21 / Spring Boot 3.3 with PostgreSQL, Redis, Flyway, and JWT. The frontend is React Native + Expo with Zustand, React Query, and RevenueCat for in-app purchases.