“The API surface of GDK Glassware is not limited to the classes contained in the GDK Add-on. The GDK Add-on merely closes the gaps between the Android SDK and features that are unique to Glass. This means, in general, given a problem that isn't covered by the GDK library directly, just attempt the Android solution.”

compileSdkVersion "Google Inc.:Glass Development Kit Preview:19" 

 <uses-permission android:name="com.google.android.glass.permission.DEVELOPMENT"/>

openOptionsMenu()  

onCreateOptionsMenu()
onOptionsItemSelected()
onOptionsMenuClosed() 

getWindow().requestFeature(WindowUtils.FEATURE_VOICE_COMMANDS); 

getWindow().addFlags(WindowUtils.FLAG_DISABLE_HEAD_GESTURES); 

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, MY_REQUEST_ID); 

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_CAMERA) {

Intent intent = new Intent(android.content.Intent.ACTION_VIEW,   Uri.parse("google.navigation:q=your+address"));
startActivity(intent); 

Intent intent = new Intent(android.content.Intent.ACTION_VIEW,  Uri.parse("google.navigation:q=your+address&mode=w"));
startActivity(intent); 

startActivity(new Intent(Settings.ACTION_SOUND_SETTINGS));