Unlike others above, I don't completely hate it – in fact, I like some of the broad strokes of it. Here are some loose thoughts:
a) your device looks quite a bit like a dealer button, which could cause some confusion (even if that confusion is just visual). Is it possible to make it look substantially different from a button?
b) as said a few times above, the dealer button with a built-in timer already exists. Most of what I've seen (plus the one I have) resembles a $5 egg timer. If you made one that looks as cool as the one in the GIF, I'd buy it in a heartbeat.
c) I could envision the interactive nature of the capper resulting in a few "live misclicks" – e.g. someone moving the guard onto his cards (or off, to look at them), only to accidentally declare a bet or a fold or something. Perhaps the actions should be such that they are less likely to create inadvertent actions.
d) Speaking of the interactions, I would recommend making them more intuitive. Double-tap to raise, shake to move all-in, etc... you might as well go chest-sleeve-chest-chin-sleeve-ear to signal a squeeze play. Maybe your device should have little buttons on them.
e) ...or better yet, just ditch the interactions altogether. As others have said, this does not add to the enjoyment of the game; in fact, it would likely detract from it. However, keeping a built-in shot clock could be cool. A person acts, then hits their Floplay (not unlike a chess player hitting the timer button). This then illuminates the next guard in sequence. Players would always see where the action is because that player's Floplay would be glowing. Of course, the system could be such that the clock duration is adjustable – or even off.
Anyway, what is proposed in that video strikes me as trying to do too much. There is a version of this that could be rather fun (assuming it's not prohibitively priced).
Incidentally, if you guys get on Dragons' Den one day, let us all know.