Yes, much like you can on the PC game and on console, if you back up your character or world you've now got another set of items. The ability to backup that mobile received in the summer update is quite useful for making sure you have a safe copy of your player or world, as well as having the side effect that you can now go into your backed up players and worlds for twice as many items if you decide to play that way. Nothing wrong with it.You can duplicate on mobile.