I'm one of those weirdos who thinks the web has a future beyond default IE homepages for senior citizens. So I was intrigued to hear that Belly ditched their native mobile app in favor of HTML5, especially since it is specifically intended for an iOS audience. That's right - it runs only on iPads that they lock-down and distribute to their customers; yet they still felt HTML5 was the way to go. As Engineering Director Dave Arel explained, the update mechanism off the App Store left them unable to update bugs as fast as they needed to, and slowed their ability to A/B test new features.
Their UI is very rich and has lots of animation. Dave showed us how they use CSS to force hardware acceleration and bypass the browser's painting, offloading the animation work directly the the GPU.
An eye-opening look into what's possible with HTML5.