1. Download (11 MB, last update 2017.10.26) and extract the zip-file.
  2. The option 'Unknown sources' should be enabled on your Android device (under Settings/Security). Then click/tap on the filename PyQRS-4.1-Android.apk; you will be asked whether you want to install the package.
  3. Confirm; the app does not need access to personal data or peripherals. In order to show Wikipedia pages and this web page, you will need a working internet connection.