This is interesting. I hadn't heard much about the TomTom app but was seriously considering buying it. Sounds like I'm going to have to let it be tested before paying the big bucks. I must say I'm surprised no text-to-speech. That's why we'd buy the app.
I think you're confusing turn-by-turn directions with text-to-speech. Text-to-speech isn't important to a large number of people. They just want it to say turn left or right at a particular time, not necessarily the street name.