for iPhone works with standards based
VoIP/SIP servers – including 3CX Phone System, Asterisk and other
popular VoIP/SIP providers.
What’s the difference between 3CXPhone for iPhone and other
“free” SIP phones for iPhones that are available on the market
today? 3CXPhone for iPhone is not locked into a particular provider
or PBX. You are given the freedom of selection, meaning that you can
pick and choose your favorite provider or VoIP PBX, switch at any time or use different VoIP providers simultaneously.