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