Im assuming the app is the method here-or at least I can think of a way the trick could be done with a special app does anyone know if its been released?
Very good effect.

https://youtu.be/aNsRxAKMpXk?t=88

If that link doesn't go straight to effect it starts at around 1min 12.

My initial thought would be ....... the app forces a number or a specific bank of numbers, and the deck is a 'double-decker'.

Agree on first part,not familiar with double decker ,can you elaborate? Wonder if you could do it with a Svengali?

Try a search for 'The Phil Deck'

Ah yes I know of that deck.Its a double decker is it?

I don't think it is an app. I think the deck is set up in such a way that any number would work.

However, if it is an app, then I think it is an app that is designed to only allow odd numbers to be chosen. 41, 13, 47 were all the choices. This would be an even cleaner way to use the deck set up mentioned but not detailed in my above comment.

Either way, great idea and killer reaction

This is numbered by astor.