F-Stop Media Gallery - Image and video organizer.
KeepSafe - Keep your entire photo library safely stored in an encrypted private cloud.
A Photo Manager - Manage local photos on Android: gallery, geotag with photomap, tags, find, sort, view, copy...
Stingle Photos - Stingle Photos is a secure photo/video encryption and backup application that provides strong security, privacy, encryption and safely saves your media on cloud storage keeping you safe from data breaches and leaks.
LeafPic - LeafPic is a fluid, material-designed alternative gallery.
Privary - Software to hide private photos and videos.