The Callcentric Android app allows you to use your Android phone to initiate "callback" calls worldwide through your Callcentric account, and save significant money over cellular carrier calling rates. This is particularly useful to customers who want to save money on international calls using their Android phones, or perhaps want the caller ID of their Callcentric account to show up on outbound calls they place instead of their Android mobile phone number.
Behind the scenes, the Android App is accessing CallCentric's "Click 2 Dial" web-based feature.
CallCentric has done an excellent job explaining the benefits of using their Android App to save money on long distance calls from your Android based phone. Their web site gives full details of how to download and install the app on your Android device.