Clash Royale Card Maker is a small web application that allows to easily create custom cards based on the ones from the famous mobile game Clash Royale. The original website was built in about three days, and a lot of bug fixes have been done since then. Supercell (the company behind Clash Royale) liked the website so much that they decided to sponsor it various times through their official social accounts. During its first months of life, the Card Maker used to have roughly 1.3 millions users per month. After four years, the website still has around 15 thousand users per month.