Does voice navigation work on iPhone 4? I currently use a telenav app due to them having voice nav. I'm not in a position to upgrade my phone yet, so my girlfriend and I are stuck with the 4 for a bit. I downloaded the app and gave it a test but it didnt seem to do any voice -- that may be because I wasn't moving, though. It did give me the option to mute the voice navigation -- which I found odd.