[Jessekg]

That is an interesting question. I almost want to make a comment that starts with "I remember when..." sign of the times I suppose.
I also use my phone for all manner of things I could not have imagined a few years ago. With that being said, on the trail (at least the ones I ride) you can not count on reliable cell service. So a data heavy apps may not be useful on your next trip in the dirt.

My advice, a good trail map (paper) in the glove box, A CB radio (since you most likely don't have cell service) to talk with your buddies and other groups on the trail are best for off road applications.

 

[Jessekg]

GPS app, good idea.

I will have to check that out. I agree having GPS is nice to mark way points (so you can find your way back a year later when can't remember which trail number you went down last time...). I have an old Garmin hand-held I use for both hiking and trail rides.