Thoughts on rss.app?

I'm trying to build up my feed using rss, but some sites just don't have it or doesn't let me filter through it as thoroughly as I want to.

I found this website, rss.app, that seems to be the solution to these problems, but I never really heard of this site before. Is there anything I should know about it?

I'm asking because the site requires you to make an account there to use it which asks for your name and email address and I don't want some random company spamming my email.