Hopper is a new, free iOS app that predicts airfares, so you can figure out the cheapest times to fly to your destinations of choice. The app provides an uncomplicated look at what can be a complicated, maddening even, subject \u2014 airfare. It has already earned a place in my iPhone's travel-app folder.\nHopper is simple in its approach. You don't have to create an account or sign in with Facebook. You just give it access to your location and start a search by telling it where you want to fly. The app delivers a month-by-month, color-coded view of airfares. The calendar is located below a "fever" bar, which displays a range of the cheapest and the most expensive prices. Hopper's airfare prices are for coach; I see no option to research business or first class fares.\nViewing calendars makes it easy to spot bargains right away, and they can save you time and reduce aggravation. The app also make airfare predictions based on chosen dates.\n\nFor instance, I picked dates for possible trips to Greensboro, N.C., and Myrtle Beach, S.C., from San Francisco. Hopper told me the lowest airfare available right now for my Greensboro trip was $452, that I should "book now," and I "will likely pay more" if I wait. Then again, Hopper told me to book now for every itinerary I researched, so I'm taking that advice with the proverbial salt grain.\nThe app also told me it would be $92 cheaper to fly to Charlotte instead of Greensboro, which was helpful information. When I chose a departure flight, Hopper told me I "could do better." Specifically, it said: "You can fly at a better time of day for about the same price," then showed me a later flight. (Hopper even predicted I'm not a morning person.)\nAfter you find what you want, you can use Hopper to book flights via Travelocity, Orbitz or the relevant airline. You can also opt to hold off on booking and receive notifications on your iOS device when fares drop.\nWhat doesn't Hopper do? For starters, it's only available for iOS and isn't optimized for iPad. You don't get a lot info on the flights other than flight numbers, departure and arrival times, and the number of stops in an itinerary. There's no way to share your potential itinerary with others, a helpful feature that's available in Kayak and other similar apps. If you're undecided about where to go next, Hopper also doesn't let you simply browse low airfares from your home airport, like Skyscanner does.\nHopper is tightly focused on a few select goals, and within that focus it delivers. As a seasoned airfare-bargain hunter, I know it's never wise to rely on a single app for everything. I expect to begin future airfare searches on Hopper, then check Kayak, Google Flight Search, Airfarewatchdog, Hipmunk and SeatGuru to make sure I'm getting what I want.