Android app to make and receive automated phone calls on mobile telephone network.

In order to test mobile phone calls between various phone networks, we want
an app that can:

- run as an agent on android phones (owned by us).
- regularly download config from a server on the internet.
- make and receive unattended phone calls (over GSM network) based on downloaded config.
- post calls logs of made and received calls to a server on the internet.

We would provide the internet server API the app uses to download instructions/config from and upload call logs to.

We need to know if this is possible and what approximate cost would be for a
basic product.

Additional functionality we would be interested in includes:

- ability for the app to answer a call and keep the line open
for a certain number of seconds

- ability for the app to detect when a call is answered by remote party, gets
busy signal, "not connected message", etc

- ability to receive VoIP calls on the phone and terminate these calls on
the mobile phone network (make a call and connect the incoming call to it).