All-India College Study App

I am building a cross-platform study hub where students can browse, read, and download books and notes from every college in India. The interface must switch smoothly between English, Hindi, and any future languages we add, so please architect localisation from the start. I need native-quality apps for iOS and Android plus a responsive web version that share one code-base as much as possible; Flutter or React Native is fine as long as performance and store-submission standards are met. A slim, secure backend should power user management, content search, and fast file delivery. Users will sign up with their phone number only; OTP verification is mandatory for every new device. Key deliverables: • iOS app, Android app, and web portal compiled from the same project • Admin dashboard to upload, tag, and moderate PDFs or scanned notes • Multi-language UI strings loaded from a single source of truth • OTP phone authentication integrated with an Indian SMS gateway • Clean, documented APIs and source code so my in-house team can extend modules later Please outline your proposed tech stack, timeline, and any similar work you have shipped.