On iOS, there's the FILES app, and if your app writes anything to it, it'll propagate to all devices.

I notice in the Google Files app, there's a "documents" folder. If I give the user the option to save data into that folder, will it automatically sync between their devices in the same was iOS does? I'm looking for the simplest way to give the user the option to save their data somewhere that will sync to all their devices.

CodePudding user response：

The closest thing is autobackup. This is meant for installing an app on a device, or uninstalling and later reinstalling. It isn't really meant for syncing, as figuring out conflicts without being the app developer would be nearly impossible. Cache coherency is a hard problem. THe docs for Google's Auto Backup feature are at https://developer.android.com/guide/topics/data/autobackup

Anything stored in the app's internal or external storage will be saved, as well as any dbs in the default db directory and any shared preference files. Files in the cache directories are not backed up. There is a 25 MB limit per app for backup. If you are over 25 MB, your app will be notified but no backups will be made until you're under 25 MB again.