Warning: works only on older android phones <5.0, which let programatically to turn on off the DATA without rooting the phone.

Are You tired switching off mobile data manually?
- Let this utility app to do it automatically for You!

Smart principle:
It automatically will switch OFF mobile DATA when phone SCREEN goes OFF!

FREE. No ADS. No in App Purchases!

That's cool, because:
Switch Off SAVES battery power.
Switch Off SAVES costs spent on Your plan for mobile data.
It's healthy for You! - as phone won't transmit mobile data in Your the pocket:)