Chrome Cast. There is no OS-level service for it to introspect the network looking for screens to cast to, so each app has to drop in a SDK - which then has to have permission to search the local network looking for screens.
This was improved in recent iOS, but I never count on Google updating their SDKs to take advantage of iOS features on any sort of schedule. Even when they do, it will require third party apps to individually update as well.
This was improved in recent iOS, but I never count on Google updating their SDKs to take advantage of iOS features on any sort of schedule. Even when they do, it will require third party apps to individually update as well.