App says "please wait"

Hi there,

My shiny app was running perfectly well for I'd say almost a year, at least 6 months.
Now when I try to access it (or other people from other computers) it says "please wait" for eternity.

I have not redeployed the app recently . I haven't changed anything from my side. As I understand all of the files are uploaded on some Shiny server. So I don't know what has happened.

Any advice ?
The web address is below.