Mobile Data block

Since version 4 of Android (it was already in 2.3) you can monitor your Mobile Data usage. If you are like me and need

Mobile Data (2G/3G/4G) for urgent messages you maybe don't want other apps to exploit your Mobile Data connection,

or at least have some control over it what app can use it.

On the store there are many so called Mobile Data Firewalls. They work well but I don't need another app.

Because it is already provided in Android 4.x but limited to Background Data. That is data that is used by an application

when it is not your current application when the screen is on.

Goto your System Settings and Select Data Usage.

Select the Mobile tab and you will see how much data is used in the period you selected. Here you can set limits for Warning and Turning it Off after reaching your Data Limit.

If you scroll down you see the applications and the amount of data they have used over your Mobile Data connection

in a given period.

Now tap on the application and you will see the data usage over that period for that application.

Scroll all the way down and select Turn Off Background Data only for Mobile Data Network.

Only Wifi will be used now for that application.

So you don't need a Data Firewall with Android 4.x if it is Background data you want to block.

It is already built in.