Where to see how much MB/GB of internet left in "Mein o2"?

Hello to everyone!

I have tried for the first time the "Mein o2" application.

Mein o2 - Android Apps on Google Play 
As you can see from the pictures in the link, it's supposed to give the information about how much internet I have left (verbraucht). Unfortunately, I can't find such thing in the application, which made me feel stupid. Please, help me finding a way to check how much data I have left. It can be via app or PC.

Also I noticed that in tarif info it shows that I have a "o2 Loop Smart" tarif, which is correct, but it shows that it includes 200MB/month which is an old info, because it actually is 750 MB since last year. Not that it buzzes me, but it wouldn't hurt O2 team to "comb" the app a bit for a more actual data.

Thanks in advance for your replies and assistance!