Wren - Offset your carbon footprint by saving rainforests
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
YAYZY - Track the carbon footprint of each purchase in real-time
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Klima - Go carbon neutral
LightShot - The fastest way to take a customizable screenshot.