GasBuddy

I've used the free (I love free) GasBuddy app for several years to look around for the best gas price, but when I checked a few days ago I was amazed to find a gallon for $1.16, a price last seen in the 1990s.  Costco is almost always the least expensive, but in normal times they are usually 25-30 cents less and worth the wait in line.

https://www.gasbuddy.com