The Whoopsie Twirl is a one card twirl based on an old wand spinning move, only done with a single card. Plus, three simple, short flourishes that utilize the Whoopsie Twirl.
I came up with the move independently a few years ago, and since then (and maybe even before) a few others have come up with similar variants - in fact many non-flourishers even do similar moves playing around with their phone. This is simply my personal styling on an old pen spinning move, adapted to a card.
Credit to: Dan and Dave Aaron Fisher Ben Coy
Recently the 'Half Tonne Twirl' was brought to my attention - I hadn't noticed this before making the tutorial, so I've added the creator to the credits after the fact.
While the move is similar, the mechanics are different - the card is turned or twirled with two fingers to move to card, and also moves the opposite rotation as the Whoopsie Twirl. The Whoopsie twirl turns completely on pivot points, and is held only by the first finger and thumb.
Regardless of that clarification, I still think his move is awesome, and very similar in it's look, so I've added him to the credits, and you should go check it out if you like moves of this nature!