A free app for Android, by Sweet Sugar.

Mobile Number Tracker is a free, easy-to-use application that lets you view the information regarding any phone number in the world, including the country, state, city, and even the exact location. You will be able to find out all of this information in just one click. The application is designed to work with any phone number, regardless of the country or network it is in. 

Once you find the number you want to track, you will be able to view all the information regarding the number. You will be able to find out the country, state, city, and even the exact location. You will also be able to find out the phone type and the network.