use right android app id

src/vector/mobile_guide/index.html

@@ -235,7 +235,7 @@ body {
               </a>
               <h3 class="mx_Spacer">Android</h3>
               <p>If you have an Android device, install the Android Riot app from Google Play or F-droid.</p>
-              <a href="https://play.google.com/store/apps/details?id=im.vector.alpha" target="_blank" class="mx_ClearDecoration">
+              <a href="https://play.google.com/store/apps/details?id=im.vector.app" target="_blank" class="mx_ClearDecoration">
                 <svg width="162px" height="48px" viewBox="0 0 162 48" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
                     <!-- Generator: Sketch 51.2 (57519) - http://www.bohemiancoding.com/sketch -->
                     <desc>Created with Sketch.</desc>