Roadmap

Speech recognition

https://stackoverflow.com/questions/4734030/voice-to-text-on-android-in-offline-mode

// Check to see if a recognition activity is present
PackageManager pm = getPackageManager();
List<ResolveInfo> activities = pm.queryIntentActivities(
        new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0);
if (activities.size() != 0) 
{
    speakButton.setOnClickListener(this);
}
else
{
    speakButton.setEnabled(false);
    speakButton.setText(R.string.recognizer_not_present);
}

https://stackoverflow.com/questions/5402003/converting-speech-to-text https://developer.android.com/reference/android/speech/RecognizerIntent.html

https://stackoverflow.com/questions/19564561/does-the-google-speech-recognizer-on-android-need-internet