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…
I can only speak for myself and a handful of other people I know who are into FOSS, but for us we care more about it being functional than looking pretty. I just want to see what I’m getting into, a reference for what a successful install looks like, or just check to see if it’s got the buttons I want on it.