My suggestion is to not worry about apps and digital devices and instead use common sense and forethought. You have a small trailer, you should be fine just about anywhere. Remember that all those gas stations get their fuel in large, tall, long tanker trucks that are able to get into and out of those gas stations just fine.
Start looking for gas when you get no lower than a quarter tank. Driving on the interstates will give you a wide selection of gas stations. Driving on local highways will give you less of a selection.
Plan ahead before pulling in to a station. Look for other entrances/exits and ensure that you park your rig so as to allow for easy path to exit when you are done. I prefer the pumps at the end of the line so I am less likely to obstruct other customers while I am there. Don't forget to swing wide when turning, so you don't hit anything.
Again, a 25' trailer is relatively small and you shouldn't have any problems with most gas stations. Know your height, including AC, and watch for low canopies and low clearances.
Enjoy your trip, congrats on your new RV!!!
