I beg you, if you are a developer of an open source app or program - add screenshots of your app to the README file. When looking for the perfect app, I had to install dozens of them just to see what the user interface looked like and whether it suits me. This will allow users to decide if the app they choose will suit them… Please, don’t think about it, just do it…
Yeah, it’s a thing :)
I’ve only done it once, and it wasn’t pictures, it was rewriting a horrible section about how to install a program my cousin was trying to build. He abandoned it three months later, but still.
From what I’ve heard from people that code, it’s polite to approach whoever is maintaining the project before jumping in, and it makes sense so that nobody wastes resources on something that isn’t going to get used.