If the abbreviation API doesn’t mean anything to you, then this blog post isn’t for you.
The stacks project website has (the beginnings of) an API. This can be used to write a mobile version of the stacks project website, a webapp, a phone app. These apps could perform any task you think is fun (see PS for a suggestion).
But here is what is really cool! If you decide to write something like that you’ll be the app developer for the Stacks project as you’re almost guaranteed to be the only one (since after all you’re the only one still reading this blog post). This will get you huge kudos and nerd points with all your friends!
You can just go ahead and do something, that’s fine. It may help to contact Pieter Belmans to coordinate issues about the API.
PS: Recall the “slogans” we discussed a while back. Here’s an idea of a web app to crowd source these slogans: there’s this page somewhere on the web and if you go there it throws up a random lemma, proposition, theorem from the Stacks project. Under it there is a text entry box where you can type your (proposed) slogan. These slogans are remembered by the app and if the random result already has a slogan, then it can be updated by the next visitor. Sounds like fun.
PPS: Online quick search and quick tag search apps are somewhat more obvious ideas.