Hanalei Group Vacation Finder is a React app in the style of AirBnB and topfloor.us.
I play a lot of tabletop games. Many of these have complicated scoring mechanisms such as "if you have this type of card group them into unique sets. Then square the number in each set and add the numbers together to find your score". It's easy enough to reason about but we'd rather not have to write it down every time.