Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Annotable - Ultimate image annotation & markup tool
GIMP - GIMP is a multiplatform photo manipulation tool.
Hover Me - Hover me lets you quickly annotate any image and easily integrate an interactive version within your own website.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Picsell.ia - Annotate datasets smarter, 10x faster & cheaper.