I don't know if there is an app for this or not, but I'll put my suggestion forward.
The app would utilize text to speech to read text messages out loud, as well as use voice commands to "reply", "foreword", "call" etc. in addition to the speech-to-text capabilities of the Android phones.
It could also perhaps integrate with the music player to allow basic voice commands such as "play", "next", "back", "pause"
If such an app exists, could someone please point me to it? If not, it's just something to consider.