Tudzu is a must have apps if you want to exchange the multimedia files or if you want just a back up. You can exchange the files on a private network with your friends or families. You can join an already existing group or you can get invited to a new one. You can choose the files to protect or to share and you can ban the subscribers whenever you want to. Every group you join will be protected and you can choose the content to share with any of your group. The files you send or you store are all encrypted for security reason.