mmazzarolo/breathly-app ? reverse-engineered prompt

Build me a tiny mobile app for iPhone and Android that helps people focus on their breathing and relax. I want a simple experience where the user can choose a breathing technique, start a guided session, and follow along with a smooth breathing animation and clear timing cues. It should feel calm, clean, and easy to use, with just enough detail to support daily breath training without getting in the way.

Please make it in React Native with TypeScript, and keep it lightweight and polished. If you need to check current docs or best practices for anything, look them up online. I also want the code to be easy to understand and maintain, since this is meant to be a small open source project people can learn from.