talkmagic.co.uk

Hello guys I saw a trick on an instant download section of a website but I can't for the life of me remember which one. I was hoping someone may know what it is I am talking about and point me in the right direction. It is a colour change where a card is turned blank by running your thumb over the card. Unfortunately I can't remember what the love is called. I have worked a similar method out but need to buy it anyway. Any help would be appreciated if possible