App not opening and not even their website

This app claims it found 430 error codes (seems to be an unused error code from my Googling) on most all of the pages of the two sites I'm using it on, and it suggested redirecting absolutely fine live pages, products, and collections! This could be dangerous for less experienced merchants. I just want to see any 404s that may be happening after re-themeing and re-organizing the sites, and there's no way to just view 404s, or dismiss those weird 430 errors. I am not impressed with this app and I guess I'm getting what I paid for.