These self guided tours were fantastic. Liked how flexible they were, the added information for restaurants and what to spend time on and what not to. Two suggestions: you need to give more notice on upcoming turns and maybe offer landmarks to look for the turns. Second, the south island tour is too long. You should take Kona and the beaches before Kona out of it. Definitely so not include the volcanoes in the south island tour. There's no way of doing the whole tour in a day.
Otherwise, this was the first time using the app and thought it was fantastic.