I use Gas Buddy to find nearby stations, but back it up with Google Earth to make sure I can get in and out. Track stops such as Pilot, TA Flying J and Loves are all easy to get in and out of, but the truck lanes are pretty disgusting. If you're using gasoline, you can avoid this issue. Most of the Pilot stations have a big lane for trailers.
AllStays app for your phone will find almost anything RV related, but I found it difficult to follow the directions given by this app. MyPilot finds Pilot and Flying Js and Truck Smart locates TA centers.
Co-Pilot GPS app for RVs lists truck stops in the points of interest menu. Supposedly, this app will also keep you off roads with low clearances, although I haven't tested this feature yet.
TIP: You should put a description of your rig in your signature so we'll be able to answer better.
