This is an Android App for studying for your german Amateurfunklizenz. You can find the app on F-Droid and Google Play:
It is based on source code from Matthias Wimmer
https://github.com/mawis/sailtrainer
The questions have been extracted from AFUTrainer by Oliver Saal. The questions XML files can be found at
http://oliver-saal.de/software/afutrainer/download.php
The Lichtblicke PDF is available at https://www.dl9hcg.a36.de
Thanks to everyone for making your projects available.
The questions license is according to German official publications
(§5 UrhG) as well as formelsammlung.pdf.