This is just crap. Why would you want something that can give you wrong answers (like 4 out of 20 like in the tables, that is much!) - in an emergency?
I recently saw in a documentation, that jam was banned from german prison(s?) because you can use it for making alcohol. So might not be the first product which got banned because of this.
Niche topics are often fascinating in their own way, even if you've had nothing to do with that niche before or won't have anything to do with it afterward.
Why... Maybe the website is the thing that's the least fun or the least important and that would be a good fit for delegating that work to an AI, isn't it?
Spider Solitaire is very nice, I really would recommend Simple Solitaire Collection for Android on F-Droid. It has 17 Modes, Spider included and you have settings, for Spider for example you can choose from 1, 2 or 4 different card colors to make it harder.
I really like a small or larger comment above each function and more, even if people often say "less is more" - I disagree. Comment everything! It won't hurt. And people who don't like it can remove them and feel mighty.