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

Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

Shutter - Shutter is a feature-rich screenshot program.

Live Chat by Sumo.com - Instantly communicate with customers, prospects & visitors

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

Zendesk for Startups - Everything you need for seamless customer conversations.