Sign up here and we’ll help you along the way as far as setting up the SIP on your smartphone
You can always change this later but choose PBX as its the virtual phone system and has all the forwarding options anyway.
A free one is zoiper but we really like groundwire. Yes, its very reliable and we pride ourselves on impressing our customers with high quality SIP calls over 3G/4G networks
Thanks and let us know if you have any other questions