title: Confusion about signing android app
body: <p>I am about to publish my first android app. 
  For that I have to sign my app. I followed the steps, described here ( <a href="http://developer.android.com/tools/publishing/app-signing.html" rel="nofollow">http://developer.android.com/tools/publishing/app-signing.html</a> ), under the point 
  "Signing Your App in Android Studio". 
  At the end it said, I received a signed .apk
  Under the point "Signing in Release Mode" it also says, I have to edit my gradle file as shown there. </p>
  
  <p>First question: Do I have to do both? So do I have to put my keystore and key I obtained via the other way in the gradle file, or is that just another way?</p>
  
  <p>Second question: Under the point "Automatically Signing Your App" is described another way for signing. Did I understand it right, that when I follow the steps described there, so put in my keystore/key I obtained with the other tool, Android Studio automatically generates the updated .apk everytime I build my project, and otherwise when dont using this tool, I would have to follow the steps of "Signing Your App in Android Studio" everytime again manually?
  If so, where would it save the updated .apk, since I cant specify an output directory, and already have my first signed.apk</p>
  
  <p>Third question: Since I did get my signed .apk, I actually have to enter new Api Keys for Google Maps and GCM. But when doing this, and trying to install the app on my phone via USB, I get the exception, that I use a wrong API Key, but when I use my old API Key, I got with the Debug certificate, erverything works. So it seems like Android Studio installs the debug.apk, although I signed the app. </p>