This may be of special interest to those who enjoy magic, whether with playing cards or coins - and even both!
Mechanic Industries have released several unique decks with an industrial styled design, with two special features: (1) flipbook animations, where the cogs on the back design move; and (2) a secret marking system. So yes, this is a marked deck, and the cog rotation can be used to identify both the suit and value of the cards. You can preview how this works for free - download a PDF from the publisher explaining the marking system in detail here.
But of special interest to those who enjoy coin magic will be the fact that Mechanic Industries has also found a way to integrate playing cards with coin magic. They've made their own grinder coins, and which appear on the cards themselves, giving lots of possibilities for making coins appear and disappear from the cards as part of a routine. Each of their deck has Jokers which picture these coins or have blank areas where the coins would be, and this can be used for a whole range of effects that combine the playing cards with appearing and disappearing coin routines. They also make these routines for both coins and cards available online via their Workshop. About half of these video tutorials are entirely free, while the other tutorials are premium tutorials.