Dialpad - Switch is a cloud-based phone system built for Google Apps users.
MeetingMogul - Join any conference call with one-touch
GlobalMeet Collaboration - From cloud PBX to conference calls and meetings to online events, GlobalMeet is a business communications platform that helps take you where you need to go.
CALLR - CALLR is an extremely helpful app for those who have to deal with call control protocols for their business. You can create a customized call control system that will perform a wide range of functions.
MiCloud Connect - Secure and flexible cloud phone services and unified communications.
MobileDay - MobileDay provides one-touch access into conference calls and online meetings from iOS or Android devices.