[asterisk-users] Redirect a GSM call through Wifi to a SIP phone

[Sil]

Hi all,

I've try to search Google about this without any chance.
I want to know if it's possible to use a mobile phone application for 
redirect automatically incoming calls of a GSM phone connected to Wifi 
network to a Sip phone.
I've try to use different mobile phones SIP clients without any success. 
No one of them can redirect calls automatically. I've got Android and 
BlackBerry phones.
Thanks.
Sil