The app for the Basic Law of the Federal Republic of Germany contains the current version of the Basic Law: clear, searchable and with a personal memory function for saving and collecting the most important articles.
The 14 sections of the Basic Law are preceded by a short introductory text that provides an easy-to-understand overview of the most important provisions of each section. The app also offers a lot of background information on the creation and development of the Basic Law. Why is it actually called the Basic Law and not the Constitution? How and when was it decided? How can it be changed?
As an bonus there is the bpb lexicon "Pocket Politics", which explains political terms briefly and understandably: from "member of parliament" to "immigration" and some surprising information about the Basic Law.