Under Android, it's possible to get a list of all installed applications by querying the packageManager: https://developer.android.com/reference/android/content/pm/P..., int), rather than "brute-forcing" known URL schemes. This doesn't require any special permissions.
Doing it this way means it'll work on iOS and Android, and it'll continue to work if the installed applications API is ever removed or blocked by a permission. Using the URL scheme essentially can't be blocked because it's necessary for inter-app comms.
