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!
LightMV - LightMV is the best free online service for you to make a video using photos and music.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
4K Slideshow Maker - Free app to create slideshows.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Photopia - Photopia is the official successor to ProShow. Find out how you can easily transition to the next generation of slideshow software.
JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.