I was in China a couple of weeks ago for the Google Developer Day and I was showing everyone my QRCode scanner, it was working great until I went offline. When the user was offline (or partially connected) the camera wouldn’t start, which meant that you couldn’t snap QR codes. It took me an age to work out what was happening, and it turns out I was mistakenly starting the camera in my onload event and the Google Analytics request would hang and not resolve in a timely manner.
Eric Bidelman on Google Developer’s Web updates, writes: Building for the web is a rocky adventure. It’s hard enough to build a top-notch web app that nails performance and uses all the latest best practices. It’s even harder to keep that experience great over time. As your project evolves, developers come on board, new features land, and the codebase grows. That Great Experience ™ you once achieved may begin to deteriorate and UX starts to suffer!