DecSync CC synchronizes contacts, calendars and tasks using <a href="https://github.com/39aldo39/DecSync">DecSync</a>. It stores this data in a shared directory, using Syncthing, Google Drive, Dropbox or any other file synchronization service. <a href="https://f-droid.org/en/packages/com.nutomic.syncthingandroid">Syncthing</a> synchronizes files directly between devices, without storing the data centrally or requiring a server. DecSync CC works with any file synchronization service, but using Syncthing is recommended as your data stays on your devices. The UI is based on the one used in <a href="https://f-droid.org/en/packages/at.bitfire.davdroid">DAVx⁵</a>.