S2 Neon is a softphone application to make VoIP calls from mobile phone. S2 dialer can run smoothly in any version of android phone. Works In Lowbandwidth, Low Data Consumption, Codec Support: Supports G729, G711, GSM and AMR codecs. IP Traversal: Runs behind NAT and on private IP. Protocol: Session Initiation Protocol. Compatibility with All softswitches.