Oh yes, our friend gas buddy. We use it all of the time and I think it's a good app, but I do remember one time in Canada this summer. I think it was in Whitehorse, where fuel isn't cheap, we found one station that had a good price on GB. When we found it, someone must have fatfingered the price because the last two digits were backwards. The real price ended in .73 instead of .37 as someone had entered. That would have made a $36 savings on a 100 gal fillup.
And in the larger towns (meaning larger than one or two streets) we found it paid to go looking around. Usually in the industrial areas, or back off of the main highway where the truckers and tourists are, the stations there that are serving the locals have lower prices because the locals will go shop around. You're on vacation, take some time, see the towns, find a lower fuel price.
Bill