Notification names are arbitrary strings. It's convention to use "fully-qualified" names like that to avoid collisions. In this case, I imagine that just happens to be what the developer chose as a prefix.
The whole point of reverse DNS notation is to have a conflict free namespace though. Using somebody else's namespace is asking for trouble in the future.
In this case it's probably additional subterfuge in case somebody examines all notifications posted and sees apple and thus ignores it.
