Monosnap - Monosnap is a comprehensive screenshot taking software system that provides users with a fast and accessible way to take screenshots whenever they want. Read more about Monosnap.
Workona - A better way to work in the browser.
Annotate - Annotate (formerly know as Glui) is the simplest way to capture, annotate and share screenshots.
OneTab - Whenever you find yourself with too many tabs, click the OneTab icon to convert all of your tabs into a list. When you need to access the tabs again, you can either restore them individually or all at once.
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Session Buddy - Manage Your Browser Sessions