Call tracking works with the Twilio API, so you'll need an account and phone number at Twilio before you can get started. Twilio sells simple, pay as you go phone services, sign up at http://www.twilio.com.
This is a port of the php project at https://github.com/Beans0063/Twilio-Call-Tracking/
Presently the Twilio call flow is here, but there is not yet any ui.
You'll need an account at http://www.twilio.com. Set your Sandbox phone number or purchased number's Voice URL to http://www.yourserver.com/calls/incoming_call.
Also, set the forwarding number as AGENT_NUMBER in environment.rb
Released under the MIT license.