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.
Adobe Bridge - Download Adobe Bridge CC digital asset management software when you get started with Adobe Creative Cloud. Start your free trial today.
Google Photos - All your photos are backed up safely, organized and labeled automatically, so you can find them fast, and share them how you like.
Apowersoft Photo Viewer - Apowersoft Photo Viewer supports various image formats and PDF files. You can also process images in batch, take screenshots and upload/share images in seconds.