Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Snip&Sketch - Quickly annotate screenshots, photos and other images with your pen, touch, or mouse and save, paste or share with other apps.
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Apowersoft Free Screen Capture - Apowersoft Free Screen Capture is the free online screen recorder that allows users to do unlimited recordings within a few clicks.
LightShot - The fastest way to take a customizable screenshot.
NinjaCapture - All in on Screen Capture