title: How to manually verify apk signatures and compare signing keys
body: <p>Suppose I have two .apk files, supposedly from the same developer.
  How do I verify that they are signed with the same key?
  How do I verify that the key belongs to the developer?</p>
  
  <p>In which Android download does the right tool exist?
  I do not seem to find it in 
  commandlinetools-linux-6200805_latest.zip nor 
  android-studio-ide-192.6392135-linux.tar.gz</p>