It IS a great app – FontBook™ Typeface Compendium Review

As a designer, I find this to be an extremely useful app. I am on an ipad2, and it works great. It's fast enough, it's well-designed, it allows you to compare fonts with each other with your own text. You can search in all the ways designers search for fonts online. And it works offline, too. There is a learning curve, but if you tap around enough, you will figure it out. It's definitely worth the price.
Review by jcarucci on FontBook™ Typeface Compendium.