Why not try and sit your teen in front of a computer an read this tutorial on learning how to program an app? Of course they don’t write these things in German. In fact most of the really juice tech info online is not in German. It’s in English. What better way than this to drive home the necessity to learn English if you want to learn what is going on outside your country?
Here is Ray Wenderlich’s page – he get’s your kids started on writing their own applications on a Mac.