HyperCard combines graphics, scripting and persistence into an innovative approach to application programming.
I've started documenting stacks before. website 
HyperCard Pattern Language copied the look of Alexander's book while offering a few patterns of programming with an idealism to match the original.
People, Projects and Ideas captured the top-down authoring style that informed wiki years later. It was a who, where, what database about engineers sharing technology.
Greed in HyperCard prepared for an object-oriented programming contest at OOPSLA'89. I was quoted as saying HyperCard is object-oriented but you don't get to choose the objects.
Air Morse generated wave-shaped morse practice text intended for live broadcasts that never happened.
Gears computed the wheel ratio for each of my bikes. Included a simulator where you could pedal in each gear.
Wyatt Ride Guide provided a turn-by-turn visualization of popular rides using the non-linear view made popular as a New Yorker magazine cover.
I wrote many stacks for my kids. I would solicit requests which would be wildly fanciful. I would negotiate that down to something that fit HyperCard and would be interesting to do in an evening.
Good Bye Bad Giraffe was a story book where young Patrick made up the story.
Four-Function Calculator that worked on apples displayed on a table in a 3d image. Add and Subtract were always by one. Multiply and Divide were always by two.
Game of War expressed as a stack that played the card game by itself. All state was in fields which were organized into layers expressed as cards.