Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Boomerang for Outlook - Boomerang for Outlook offers email productivity tools to track, schedule and send mails at the right time.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Covideo - Covideo is a Video Email Platform for Businesses that enables companies to communicate quickly and effectively with their customers.
HelpScout - Help Scout is a simple, straightforward way to provide excellent support
Outlook4Gmail - Outlook4Gmail provides easy synchronization of your Outlook and Google accounts