On Windows, my most common use of the start menu is to tap the windows key and start typing out some math. The issue is that Windows isn't actually solving that math locally, but showing you the Bing search results for the expression. This has annoying latency, means you need an internet connection, and doesn't work for expressions that look like legitimate searches (ex 12345-2345 looks more like a zip code than math). I ended up building a lightweight desktop app with Rust/Sciter/JS that listened on Win+` and gave instant solutions. Was more of a fun exploration of the windows apis, but I easily use this app several times a week.
https://github.com/jpnickolas/Algebrisk