Syncthing replaces proprietary sync and cloud services with something open, trustworthy and decentralized. Your data is your data alone and you deserve to choose where it is stored, if it is shared with some third party and how it's transmitted over the Internet.
The open picker is the fastest way to get files from OneDrive and OneDrive for Business into your Android app. OneDrive-Picker-Android provides a set of Java APIs that your app can use to browse, select, and download files stored in your user's OneDrive.
RxJava wrapper for Google Drive Android API.
A unified API calls for different cloud storage providers (i.e: Google Drive, Dropbox, etc...) for Android