The thing we noticed with Pulse News Reader after using it for a month was that it got very slow eventually. Not so with Flipboard. This app, a social-media-focused iPad app, literally blazes on the iPad, making it feel like the most natural iPad news app out there. We seriously think they knocked this one out of the park. It’s currently the most popular free iPad app, and is so popular that they’re having trouble signing everybody up. That’s right, they have the digital version of a limited supply – they have API limitations. A good problem to have. source