[DennisOS2]

Is there a file manager that can sync any two folders regardless if the folders are on the device, SDcard, other devices, cloud? Need to sync to all four locations (depending on types of data) from the other of the four locations.

Back in the stone age (DOS) we used to do it easily with Norton Commander. Haven't found anything in Android.

[Rukbat]

[Moved to Ask A Question - AndroidApps is for developers to advertise their apps]

There are programs that can do that, but only if you sync the phone with Google, then keep everything synced to that. (Karen's Replicator was better than Norton - and it was open source. Karen has passed on, and Joe Winett is still maintaining the site. And the program has just been updated.)

If you're looking for full-time, active bidirectional sync, no. You'd have to develop that on your own. FolderSync sort of does it, but folder to folder via a cloud account.