In our POI Finder app "Where To?" I'm using -canOpenUrl: to detect if compatible directions apps are installed. There are more than 50 supported apps, many of them available in a multitude of country-specific versions with respective country-specific URL schemes.
In WWDC session 703 (Privacy and Your App) it was only mentioned that we can white list the needed URL schemes in LSApplicationQueriesSchemes in Info.plist. Also the mechanism for legacy apps built for iOS 8 was described. (The first 50 probed schemes are implicitly whitelisted.)
What was missing is a statement about a maximum number of entries allowed in the LSApplicationQueriesSchemes array.
We need more than 50 different URL schemes to test for all countries the app is deployed in.