Android App that can make calls

Closed - This job posting has been filled and work has been completed.

Job Description

I need an app built that can make calls using voip wi-fi and mobile 2g / 3g / 4g .
Looking for something similar to this http://twilioapplications.com/android-apps/
We don't necessarily need to use twilio.
I would like it for android and apple.
thanks.