There are many great "apps" for RV travellers. Most are free and some may cost a few dollars.
FUEL FINDER - search by zip or "nearest". Selectable for fuel grade and diesel.
GOOD SAM CAMPGROUND DIRECTORY - RV Park finder.
PARKADVISOR - RV Park Finder.
CAMP & RV - ALLSTAYS - This app has just about everything you need.
ONP WALMART - ALLSTAYS - Find Over Night Parking friendly Walmarts.
REST STOPS PLUS - ALLSTAYS - Find next rest stop along the road.
RV DUMPS - ALLSTAYS - Dump stations in US and Canada.
LOW CLEARACE - ALLSTAYS - Bridge clearance for you back roads drivers.
FIND COSTCO - Cheaper Gas and Provisions.
CAMPING WORLD - On line shopping.
RV PARTS COUNTRY - RV Parts Catalog and Ordering.
YP MOBILE - Yellow Pages as you travel - Gas, Restaurants. Repairs, etc.
SKYPE - With good Campground WiFi you can Skype your grandkids.
SYGIC - GPS Navigation (Free)