Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
VOGSY - Professional service automation tool built on Google G Suite
Front - multi-channel inbox service for collaborative teams
Timewatch - Timewatch offers time tracking, expense management, resource scheduling and professional services automation solutions.
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
Krow - Krow Software is a professional service automation solution.