smartphone app for fuel

I use DAT Trucker Services on my Android. It finds both regular truck stops as well as smaller stations that have truck pumps capable of handling large rigs. It also displays prices.

I never use RV lanes at truck stops or elsewhere. Unfortunately, many RV owners don't understand the courtesies of pumping and pulling forward so others can pump. All too often I encounter unattended RV's sitting in fueling lanes while their owners are inside eating lunch. That rarely happens in a truck lane; truckers know to move their rig after fueling.