This is a Text-To-Speech (TTS) engine for the Klingon language to be used in conjunction with {boQwI'} or Duolingo.
*** Note: This is NOT AN APP itself. ***
A Text-To-Speech engine is a system component that works in conjunction with apps that want to produce spoken output. For an example of an app which can speak Klingon, see {boQwI'}:
https://play.google.com/store/apps/details?id=org.tlhInganHol.android.klingonassistant
Any app can produce Klingon speech output through this TTS engine by calling Android's TTS API, using a locale with language code 'tlh'. See this documentation:
http://developer.android.com/reference/android/speech/tts/TextToSpeech.html
Once again, THIS IS NOT AN APP. If you leave a comment that you 'can't open it', you are basically saying that you don't understand what this is.
