https://github.com/danielamitay/iHasApp
An interseting app to collect most of schemer and app Id. It also teach you how to get the app info from Apple AppStore.
How does it detect apps?
iHasApp has a large list of URL schemes, mapped to the iOS App that they identify. The framework essentially runs through all of these schemes, and determines which URL schemes are handled by the current device, and create a list of application ids as a result of successful queries. Read more here.