If you’re planning a trip, whether for business or travel, run — or maybe I should say hop — to the iTunes store and get Hopper.

Consider Hopper a Big Data tool for finding small airfares. It constantly monitors and analyzes flight prices to predict how prices will change. It uses those predictions to tell you when to buy or not to buy your tickets. Push notifications alert you instantly when fares are most favorable.

I’ve used it over the last two months to plan several trips. For example, I am going to Las Vegas in May for the Avvo Lawyernomics conference. As I am writing this, Hopper is telling me not to buy tickets yet because prices will likely drop over the next three weeks. But it also says to book before before May 1, when prices will likely go back up.

If your travel dates are not rigid, Hopper will help you plan the optimal time to take your trip. I’ve been thinking of going to San Diego on a personal trip. Hopper shows me a calendar view color-coded to reveal lower and higher priced travel times. Right now, it says, my best deal would be to travel the first week of May.

In planning another trip recently, I ignored Hopper’s warnings that airfares were about to go up. Sure enough, they went up just when it told me they would.

Photo of Bob Ambrogi Bob Ambrogi

Bob is a lawyer, veteran legal journalist, and award-winning blogger and podcaster. In 2011, he was named to the inaugural Fastcase 50, honoring “the law’s smartest, most courageous innovators, techies, visionaries and leaders.” Earlier in his career, he was editor-in-chief of several legal publications, including The National Law Journal, and editorial director of ALM’s Litigation Services Division.