digiKam - Professional Photo Management with the Power of Open Source
One Touch Share App - Streamlined photo and video sharing made interesting
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Flytographer - Beautiful vacation photos with a local photographer
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
iNZDR - iOS Live Photo Social Media app. Post and watch!