Chipit - Store and tag all your screenshots.
Roboflow Annotate - Annotate images with ease. Export to any format.
Josh Parnham - Software Developer and organiser
Annotable - Ultimate image annotation & markup tool
Yoink - Yoink is a website that makes it easier to drag and drop images and text from one screen to another. It's a straightforward site with help along the way if you aren't sure about dragging and how to place your content.
Annotate Screen - Browser based annotation tool.