FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Retrobatch - Retrobatch is a unique application for automating actions to tens, hundreds, and even thousands of images at the same time
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
AYVY - JPEG/PNG/RAW Images viewer
IrfanView - IrfanView ... one of the most popular viewers worldwide.
NX Studio - Nikon | Imaging Products | Software