XnView MP stands for Multi Platform = it is available for Windows, Linux and MacOS. It is a continuation of the older XnView Classic. In my opinion it is a great alternative to Windows photos app or any Linux image viewer that comes preinstalled. I even think it is an alternative to IrfanView. It is really fast and simple to use, supports more than 500 image formats, has built in folder browser, image converter, editor... AND MORE!
Explorecams - Explorecams allows you to search through thousands of images that people taken on specific photo camera bodies & lenses.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
FreeFoodPhotos - freefoodphotos is a free stock photo library of food and beverage photography ready for download and use in web design and high resolution print
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Obscura - DSLR controls for your iPhone
JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.