KeepSafe - Keep your entire photo library safely stored in an encrypted private cloud.
App Lock and Gallery Vault - Wish you could simply lock all your private apps on your smartphone with just a click?
Lynx Privacy-Hide photo/video - Lynx is a professional app designed to protect a hide mobile privacy.
AppLock (FOSS) - A privacy App lock FOSS application.
Hexlock - Security app locker keeps apps private with smart profiles for any situation
Photok - A safe place for your photos. It stores your photos encrypted on your device and hides them from others.