App Lock and Gallery Vault - Wish you could simply lock all your private apps on your smartphone with just a click?
F-Stop Media Gallery - Image and video organizer.
AppLock (FOSS) - A privacy App lock FOSS application.
Camera Roll - Simple Gallery App for Android, with lovely Material Design.
Hide Secrets - Hide Secrets is an app that allows hiding everything they deem confidential on their smartphone.
digiKam - Professional Photo Management with the Power of Open Source