F-Stop Media Gallery - Image and video organizer.
FotoFreeze - Restores privacy by preventing swipe-throughs in your photos
Camera Roll - Simple Gallery App for Android, with lovely Material Design.
Cluster - A beautiful and easy way to collect and view inspiration
digiKam - Professional Photo Management with the Power of Open Source
Collectgram - The best way to organize and search informations about collectibles items and purchase new ones to your collections.