The app looks really nice. Only feedback is some labels are some airline labels are missing on the search results (G2, Gingerbread).
My feedback is more specific to Hipmunk in general. I want to use and love it but the prices have been off each time I try. For instance on jetblue.com right now I can get a ticket for tomorrow JFK -> AUS at 9:30AM for $423 but on Hipmunk it's $797. I'm guessing you might be pulling the price by flight time and not flight number. There is another flight leaving at 9:30 which is $797.