Any update on this issue? If they cannot create a true "backup" functionality they should change the name on the mobile apps since its deceiving, but I hope they can find a way to make it work properly since that would be very very helpful! I always liked synctoy's language around this.. synchronize = 2-way sync (sync) echo = 1-way sync (read-only sync) contribute = 1-way sync that doesn't sync deletions, only new files & folders (what "backup" should mean)