Droplr - Droplr is a tiny application that aims at helping people share things easier.
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
ConnectWise Control - ConnectWise Control is a mobile app that allows you to instantly connect with another system from anywhere with a connection to the internet. The software not only comes in a mobile app, but it has a desktop version as well for complete coverage.
Shutter - Shutter is a feature-rich screenshot program.
OBS Studio - Free and open source software for video recording and live streaming for Mac, Windows and Linux.
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