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

Full Page Screen Capture - I built a Chrome Extension that allows you to save a screenshot of an entire webpage as an image

MWSnap - MWSnap is basically a free to use Windows snapping tools that are used for snapping any part of the screen that is currently displaying on the front of all opened programs and windows.

Screenshot Designer - Create engaging App Store screenshots

Shutter - Shutter is a feature-rich screenshot program.

Webshot - Free and Open Source screenshot website service