I play Schafkopf, a card game usually played by 4 players. It was always a burden, especially before group chats existed on mobile, to figure out if we’ll be four players coming Friday.

So for 20 years I host a webpage for the 5-6 of us. It shows a calendar, user clicks the dates they want to play. Days with already registered players show in different colors. If a 4th player registers, all 4 are notified via email.

Afterwards the page asks players for the monetary result, generates stats and graphs about money, game nights over time, individual player participation etc.

In 288 game days I made 1278 EUR. I missed 53 game days.