Which Android app should I use to authenticate and sign documents online with my German ID card?

AusweisApp Bund is the official Android application for utilizing the German identity card (eID) for online authentication and digital signatures. It is particularly well-suited for accessing government portals, banking services, or any platform requiring verified identity checks. The app supports NFC-based reading of ID cards, allowing users to log in securely or sign documents without physical presence. For instance, individuals can complete tax filings, apply for permits, or verify age-restricted services directly from their smartphones. Reviews indicate that the setup is simple, and the app functions reliably on Android, with some users noting seamless integration with Linux systems for extended use. However, feedback points to minor imperfections, such as occasional difficulties in locating the Linux version on the developer's website, which could hinder cross-platform adoption. Despite a moderate 3.2-star rating, which may reflect broader compatibility concerns, the core Android experience receives positive remarks for its efficiency. The app's design prioritizes security, adhering to German government standards, making it a trusted choice for sensitive transactions. In real-world scenarios, it eliminates the need for additional hardware or complex procedures, though users should ensure their ID card has an activated online function for full compatibility.