aTalk - An encrypted instant messaging with video call and GPS features for android.
ShoreTel - Cloud phone system & contact center software & services
Talk360 - Talk360 is a best-in-class communication utility that offers a convenient way to connect with loved ones globally.
CorvisaOne - CorvisaOne is another cloud-based communications suite that is specially designed for companies that need features for managing inbound or outbound call centres.
FluffyChat - Open. Nonprofit. Cute ?
8x8 X Series - X Series connects teams across channels and around the globe, giving you access your most critical information securely, from any location.