Glympse: This app allows you to share your location with fellow travelers, which can be handy if you're driving caravan-style or have family or friends eager for your arrival. You can select contacts and give them permission to view your location for a set amount of time. Free.
GasBuddy: Use this not only to locate the closest gas stations, with customer reviews, but to find out the gas prices at each. It's billed as "the world's largest community-based fuel app," with 60 million downloads worldwide. Free.
HotelTonight: Use this hugely popular app to search for last-minute hotel deals while you're on the road or still at home (you can search as early as a week ahead). Hotels want heads in beds, so they're willing to slash rates rather than leave a room empty. Free.
Roadtrippers: A handy route-planning app, it enables you to mark your beginning and end points, then figure out how you want to noodle around in between. You can search for all the places to eat and stay, as well as top-rated attractions along the way, and note them on your personalized map. Free.
See also: Road trips throughout America
Waze: This app is super useful for both commuters and vacationers, allowing drivers to steer clear of traffic tie-ups. It aggregates user-generated traffic and road-condition information to identify the fastest route, and it sends alerts about accidents or other snags down the road. Free.
RepairPal: Use this one at home as well as on the road if car trouble hits. You plug in the make of your car and the problem (or your best guess), and the app provides you with area mechanics and an estimate for repair. Free.
Podcast Addict (Android) and Podcasts (Apple): The hours can fly by when you're listening to a wonderful story, and there are plenty these days in the form of podcasts — about sports, politics, true crime, even old-school-style dramas (see our slideshow of recommendations). These apps connect you to thousands of options, as well as to your favorite radio shows. Free.