2025-08-08 00:00:00 Always keep track of how much data volume, minutes and SMS you have already used. The Mein Blau app combines many useful services in a single application. So you are always up to date, regardless of whether you are a contract or prepaid customer. Now to Mein Blau: Download the Mein Blau app to your smartphone now – for free, of course. And use the many practical functions to get even more out of your mobile life.