Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
Darktable - darktable is an open source photography workflow application and raw developer.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.