First of all, I really like the App and HMI. Together with the Openstreetmap data this seems to me the best Navigation app on market.
Nevertheless there are some things, that can be improved. Using this by car or by walk should make anouncements (go left/right in xxx m) in a different way. If you walk it is hard to decide when to turn left if you get the information: turn left in 300m. Also the information 2km til target is a bit far away for a pedestrian. :)
I like the idea to walk without looking at the display and find the way by listening the navigation hints.