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

Picyard - Picyard provides beautiful backgrounds for your screenshots. Simply upload your screenshot and let Picyard do the rest. Our easy-to-use interface and customizable options make it simple to create stunning images for all your needs.

Shutter - Shutter is a feature-rich screenshot program.

Pika.style - A free tool to quickly convert screenshots into beautiful website and device mockups. You can create customizable images for App Store, Instagram, and more

Snipping Tool - Use Snipping Tool to capture a screen shot, or snip, of any object on your screen, and then annotate, save, or share the image

BrandBird - Brand your Twitter content uniquely