A Photo Manager - Manage local photos on Android: gallery, geotag with photomap, tags, find, sort, view, copy...
digiKam - Professional Photo Management with the Power of Open Source
F-Stop Media Gallery - Image and video organizer.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Camera Roll - Simple Gallery App for Android, with lovely Material Design.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.