I was shocked to find the app includes overhead clearances and one can filter that down to what they are worried about.  Looks to be very thorough.  I have not yet tried it on the road but I am amazed at what I can find by sitting her in my house.  I am a little concerned about how much functionality I will find in remote locations with no cell service.  Time will tell.  I may have to update my rating when that situation arises which will be in 4 weeks.  Happy camping everyone!