TeamViewer - TeamViewer lets you establish a connection to any PC or server within just a few seconds.
Linphone - Linphone is an internet phone or Voice Over IP phone (VoIP).
AnyDesk - AnyDesk is the world's most comfortable remote desktop application. Access all your programs, documents and files from anywhere, without having to entrust your data to a cloud service.
Zoiper - Cross-platform VoIP softphone dialer for SIP and IAX systems
GoToAssist - RescueAssist, formerly GoToAssist, identifies, diagnoses & solves issues fast with our remote desktop support software. Learn more about RescueAssist today!
Sipdroid - Free and open-source SIP/VoIP Client