Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.
ACDSee - ACDSee is an image viewer that uses very little system resources, and it has a small, sleek size that won't take up much space on your system.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Zoner Photo Studio X - Zoner Photo Studio X is a full RAW editor and image organizer software. It features a bit-map editor with layer and mask support, a video editor and a full module dedicated to culling, cataloging and complex metadata management.
Polarr - MacOS, Windows, iOS, Android and online photo editing tools & free photo editors.