I recently had to do a factory reset on my Samsung Nexus. After re installing all my apps I looked at the SD drive via a USB cable. I notice older apps that I didn't re install. I believe that maybe I should have reformatted the SD drive after the reset. Is there any app that can detect those SD folders and that these are apps I'm no longer using? I would like to get rid of them cleanly without just deleting folders via the USB cable.