Sip voip app in background ?

[andreavda]

Hello there !
I'm registered to a sip voip service and they gave me a geographical voip number, but unfortunately so far I haven't found an app that supports sip accounts and can run in background, would you please help me ?

 

[jabba_29]

What have you tried?

Have you had a go with Nimbuzz?
Nimbuzz | Windows Phone Apps+Games Store (United States)