Some of the trails are a bit rough imho. You might consider your foot wear and be prepared for some steep, rocky, rooty and washed out trails. Dont' get me wrong - still enjoyed the hikes.
The only app I've actually paid money for is called "St John Off The Beaten Path". Used it a bit to figure out which fork in the path to take and found it very useful as it overlays you on the map with your gps location.
.
>
