We check this website, now lanmessenger.github.io is up and dont blocked for our system and other users of the Internet.
So, answer to question: Is lanmessenger Down Right Now? - NO! lanmessenger is up!
If you have problem with access to site lanmessenger, and domain lanmessenger.github.io is not avalible.
Clear browser cache and/or try other web browser
(Chrome, Firefox or Safari).