 check that the APK is installed, call
<code><a href="../../reference/com/google/android/gms/common/GooglePlayServicesUtil.html#isGooglePlayServicesAvailable(android.content.Context)">GooglePlayServicesUtil.isGooglePlayServicesAvailable()</a></code>,
    which returns one of the
    integer result codes listed in the reference documentation for
<code><a href="../../reference/com/google/android/gms/common/ConnectionResult.html">ConnectionResult</a></code>.
    If you encounter an error, call
<code><a href=".