Groundwire is #6 in Top 10 SIP Softphones
A fully functional business SIP client for iOS and Android that includes conferencing and transferring.
Positions in ratings
#6 in Top 10 SIP Softphones
Alternatives
The best alternatives to Groundwire are: Zoiper, Bria
See also:
Top 10 SIP Softphones
Top 10 SIP Softphones