Whether you're a teacher, student, or scientist, you'll probably need to deal with long, complex math equations at times. It's not a problem if you can just paste in the plaintext math equation, but sometimes software like Desmos don't support that.
Try pasting 3x/(5\^(e\^x)) into Desmos. This simple example shows how sometimes you can't copy paste math equations. You can manually type this one out, but when dealing with longer equations frequently, it gets tedious.
I made a free windows app that automates this process for you. Enter the plaintext math equation into it, and it'll type out into the textbox of your choosing.
https://desktoptools.net/mathinput/
This tool solves a very specific problem, and I'm not sure how many programs don't support copy pasting. If this helps you, please let me know!