What the application does is give you the prices of gas (regular, mid grade, premium and diesel) wherever you search. If you're home, you could search by your zip code or location. If you're on the road (or preparing for your trip), you can look up where you're going to find out what the prices are there. It's easy to download and sign up. With your location feature turned on, It will also let you know how far away the gas station is from where you are and provide directions if you need them.
You can sort by Distance or Price. They even include Costco. Prices appear to be updated regularly so they are pretty reliable. The listing for each gas station also provides the phone number so you could always call them to verify the price.
Please call us or stop by if we can be of assistance. Stay safe on the road.