HelpScout - Help Scout is a simple, straightforward way to provide excellent support

Zirtual - Virtual assistants for busy people.

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

WoodBows - WoodBows provides Dedicated Virtual Assistants based in the USA, Philippines, and India at an affordable price.

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

Prialto - Prialto employs expert virtual assistants that can efficiently assist you with challenging tasks.