Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
GIMP - GIMP is a multiplatform photo manipulation tool.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Pixlr - Pixlr® makes it easy to transform everyday images into stunning works of art.