Unfortunately the SDK doesn't allow backgrounding, but for the 1.7 million users running Cydia, they can install Backgrounder to keep AMBER Alert running in the

Unfortunately the SDK doesn't allow backgrounding, but for the 1.7 million users running Cydia, they can install Backgrounder to keep AMBER Alert running in the background. It has a built-in background checking utility so that it will vibrate and set a badge if you're, say, looking at one of the other pages in the application. If you background the app with Backgrounder, this mechanism continues to run as well, providing notifications every 30 minutes.