TextNow - TextNow is a mobile virtual network operator (MVNO) that provides a free phone service to users by using other cellular networks coverage.
Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Slack - A messaging app for teams who see through the Earth!
Burner - Disposable phone numbers -- now with MMS photo support
GoToMeeting - GoToMeeting is a web conferencing service offering a range of services which are available on Mac, PC, iOS and Android devices.