Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.

Chipit - Store and tag all your screenshots.

ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...

Josh Parnham - Software Developer and organiser

LightShot - The fastest way to take a customizable screenshot.

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.