add features to my android app -- 2

i have a gallery lock app , which locks images and photos using encryption and can be backup to dropbox . i need you to add the feature to : 1) add and lock personal notes and sound files which also can be backed up on dropbox . 2) view locked images and videos within the app (right now we see only thumbnails and need to unlock them to view again) 3) fix the hide app icon feature for few android versions.