I'd like to build a mobile Web app that:
- If my iPhone app is already installed, launches it by redirecting to a URL handled by the app
- If my iPhone app is not installed, displays a web page encouraging users to download it from the App Store
The problem is, I don't know how to detect whether the app is installed before redirecting. Does anyone know a trick for doing this? Maybe a JavaScript hack of some sort, leveraging the App registered URL in an iframe or similar?