Any apps to send/recieve voice calls on iphone 4?

[JoeyT1987]

Are there any apps that can use wifi to send/recieve calls using an iphone 4 for free? I heard of line2, but I believe it charges around $15 a month for use.

[monk7]

I use nimbuzz with the iPhone 4's backgrounding and use sipgate as the voip. Sipgate is free for inbound calls so I just use google voice and all my calls are inbound, works great for me!