Both AAA and AARP have helpful apps but you can also try to find good fuel prices by using dedicated apps:  AccuFuel, GasBag and GasBuddy

There are all sorts of applications to provide maps for locations, so I'll just focus on a few that I've used.  You might want to

If you need a place to hold  your travel materials [tickets, itineraries etc.], Trip Case is one such app as is Tripit’s [which has an

Nothing earthshaking here:   When traveling, I like to visit local places and good resources for doing so are:  reviews on TripAdvisor, OpenTable [for reservations

If you want to keep up to date while traveling, using various iPhone apps to do so is simple and, usually, sufficient.  I also use

I thought I'd do a series of comments about applications for the iPhone or iPad which relate to travel, either to the places we are