It looks as though Google has made offline speech recognition available from Google Now for third-party apps. It is being used by the app named Utter.
Has anyone seen any implementations of how to do simple voice commands with this offline speech rec? Do you just use the regular SpeechRecognizer API and it works automatically?
A simple and flexible offline recognition on Android is implemented by CMUSphinx, an open source speech recognition toolkit. It works purely offline, fast and configurable It can listen continuously for keyword, for example.
You can find latest code and tutorial here.
I successfully implemented my Speech-Service with offline capabilities by using onPartialResults when offline and onResults when online.