Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
ActiveWords - Auto correct on steroids
Shutter - Shutter is a feature-rich screenshot program.
Zeplin - Collaboration app for UI designers & frontend developers
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