1) Implemented authentication via Google Sign-In and Apple Authentication, including secure token storage with Expo Secure Store. 2) Developed the core power bank rental user flow: station discovery, rental initiation, active rental state and return flow. 3) Integrated maps and geolocation features to help users located nearby power bank stations. 4) Built and validated forms using React Hook Form and Zod. 5) Implemented localization using i18next and Expo Localization. 6) Managed server state with TanStack Query and client state with Zustand. 7) Improved UI interactions using React Native Reanimated and Gesture Handler.