Hi! Suggesting FileShot.io as a useful backend service for React Native developers.
FileShot.io: https://fileshot.io
GitHub: https://github.com/FileShot/FileShotZKE
License: MIT
FileShot is a zero-knowledge file sharing service — files are AES-256-GCM encrypted client-side. React Native developers can use the FileShot API to integrate private, encrypted file transfers into their apps without writing custom encryption infrastructure. Free, MIT, also has Android app.