Hexlock - Security app locker keeps apps private with smart profiles for any situation

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.

App Lock and Gallery Vault - Wish you could simply lock all your private apps on your smartphone with just a click?

KeepSafe - Keep your entire photo library safely stored in an encrypted private cloud.

AppLock (FOSS) - A privacy App lock FOSS application.

Photok - A safe place for your photos. It stores your photos encrypted on your device and hides them from others.