I have Doughertys book on the big island and also his book on Maui, along with the companion apps. I use them every weekend when I go out exploring. His map feature is phenomenal. This is a must have app for anyone visiting Maui. His book goes great along with it too, although all of the content in the all is in the book too, just easier to read a book sometimes than cycle through an app.
TrentVano about Maui Revealed