Crown Royal Regal Apple is a Canadian whisky infused with Regal Gala Apples and apple flavoring, bottled at a slightly lower proof than their standard whisky. It's often used in place of other apple liqueurs (like the much-derided DeKuyper Sour Apple Pucker) to make cocktails.
Because it's sweet and flavored (in large part artificially), Crown Royal Apple is a pretty divisive spirit. Whisky purists generally can't stand the stuff, but it's generally regarded as better than the other offerings out there. Like most of these debates, the only way to truly settle it is to try some yourself—but if you're skeptical, maybe don't buy a whole bottle.