Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
Fragment - A powerful image viewing suite with advanced metadata info
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Phiewer - Image Viewer - Phiewer is the easiest and fastest way to view your images, videos and even audio files.
Corel AfterShot Pro - Say hello to Corel AfterShot Pro 3, the world’s fastest photo workflow tool! Edit your photos up to 4x faster than Lightroom so you can spend more time behind the camera. Download a free 30-day trial today!
IrfanView - IrfanView ... one of the most popular viewers worldwide.