About Muvo
The native Music-App in Android 2.2 doesn't react to "Listen to..."-Voice Actions. Most available alternatives only play music from their own database. Muvo reacts to Voice Actions and uses the native App to play the right title from your local music archive. Later Android versions might be able to do this on their own.
(You probably don't need this app if you're on Android 4.0 or newer)
by H####:
Works with HTC Sense UI stock Music player, only app that does this right! I used mSpot until it quit working with files already on my SD. thisBetter!