I carry an iPhone but no navigation apps (except for the Maps app it comes with, which is for highway navigation.) I carry the phone because most places I go (in Ohio, Kentucky, and Indiana) have cell service so I can call my wife each night (I hike alone and, at age 72, she worries - or so she claims.)

I don't use nav apps mostly because I'm too lazy to learn how. I began backpacking before cell phones or internet, and all we had was maps. I never go off-trail any more, and the trips I take are on well-marked trails, so map-and-compass gives me everything I need.

I've got nothing against iPhones (except autocorrect) or nav apps, they're just something I don't feel a need to have complicating my life.