In addition to our website, BookTrapper now has an iPhone app that allows you to either enter an isbn number or scan a barcode. Just like BookTrapper.com, our mobile app returns buyback offers, purchase prices, and rental prices. More vendors are coming soon, but we have the major ones!
You can download our app for IOS here. If you are in a bookstore on campus, just open the app, scan a barcode, and find out if you can get that book cheaper online. This works for renting as well - many online companies rent books, and it's entirely possible that you may be able to spend a lot less online. Just tap the menu at the top left to see the different price comparison options available.