Very cool project! I’m curious how the magician would typically use this, would the scanner and an output monitor be hidden somewhere on stage or similar?
I wouldn't necessarily expect the monitor to be visual as card tricks usually just need knowledge of a couple of cards. This could be communicated through sound (e.g. discrete earpiece or bone conduction headphones) or even haptics (e.g. Morse code vibrations from a phone in a pocket).
As for the scanner, it'll depend on the trick, the goal is just to hide a camera. It could be concealed in a prop or an item of clothing. The scanning could even be incorporated into the trick, for example by sealing the cards immediately in a "safe".
Now you only have to come up with some impressive card trick that seems impossible to pull off with conventional methods.
Of course you could also come up with a better method to communicate the information than an ipad screen. Maybe a tactile signal.
Have an audience member shuffle the deck to their hearts content, then place it on a table. Tell them what the top card is, then ask them to flip it to verify. Then proceed to do the same to _the entire deck_