In Settings > Mobile you can see what surf package you have, and check on your current and previous consumption. You can see your mobile data usage for this month. In addition, you can see your roaming data usage for over the last 30 days as well as over the last 12 months shown in a graph.
Under SIM card you can see your PIN and PUK codes (Note: If you have changed your PIN code, it is not updated in the application), as well as block your SIM card.
Note: This functionality is not available in the mobile app.