GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!
Vimcal - Vimcal is the world’s fastest calendar, beautifully designed for people who work remotely and live in their calendars.
Mailmeteor - Send hundreds of personalized emails with Gmail.
Clean Google Calendar - Makes Google Calendar look nicer & launches as a desktop app
Mailivery - Reach the Inbox, not the spam folder.
Plan - Plan is a better way to organize.