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

Cheese - Cheese uses your webcam to take photos and videos, applies fancy special effects and lets you share...

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

Webcamoid - Webcamoid is a full featured webcam capture application.

LightShot - The fastest way to take a customizable screenshot.

Cameroid - Just like Photo Booth - exept is online. Have fun with your webcam. Apply text and funny effects.