[iPhone God App] It was found using the VaxPhone (Voice Changer Supported Softphone) actually

VaxPhone is a SIP based softphone to dial and receive internet phone calls. To use this app, SIP account settings from an ITSP (Internet Telephony Service Provider) will be required.

VaxPhone features:

1. Voice Changer-letting you sound like a robot, a chipmunk, a drunk grandpa, a teen boy or someone who just inhaled helium.

2. Dial/receive phone, mobile and voip calls.
3. Multi-lines feature to dial/receive multiple calls simultaneously.
4. Multi-user conference call with multi-lines feature.
5. Receive incoming calls when application is in the background.
6. Call recording.
7. Supports Speakerphone and Echo-cancellation.
8. Mute and hold multiple calls simultaneously.
9. Hold and transfer phone calls.

10. Quick-Dial for favorite contacts.
11. Manage multiple SIP accounts.
12. Call history.

13. Selectable ringtones.
14. iPhone/iPad contacts integration.
15. Supports multiple high and low band voice codecs.
16. Auto network reachability.

VaxPhone is developed using VaxVoIP SIP SDK. This SDK provides an easiest way to develop SIP based webphone, softphone and IVR systems.