+1 to that. As a user, I am tired of having to sign up for an account on a SaaS website or installing an app from Github, only to realize the UI isn't a good fit for me. This will usually result in me bouncing from the app website instead of trying it out.

Suggestion: have a non-login demo available on your website, and high-res screenshots/animed gif of the app in action on your Github repo.