A free program for Android, by Trecone Solutions.
How much data do I have left?
This app allows you to check how much data you have left in your mobile plan, whether you are from Movistar, Vodafone, Orange, Yoigo, O2, Jazztel, Simyo, Pepephone, Eusktaltel, R, Telecable, Amena, Telcel, AT&T, Unefon, Claro, SFR, or a long number of operators and countries.
How do I use the app?
The first thing you need to do is log in to the application by creating a username and password.
Once you are logged in, you will be able to see how much data you have left for that month. You can also see how much data you have left for the previous month and for the previous year.