Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
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.
GIMP - GIMP is a multiplatform photo manipulation tool.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Polarr - MacOS, Windows, iOS, Android and online photo editing tools & free photo editors.