Big shout out to @Jimxenus for being a bigger help than I am!
@Phil_Panfili, I think I’ve corrected the links now.
Incidentally, there’s been a newer version for a while up on the web site, but not the Play Store, with a settings screen off the hamburger menu (the upper right menu), allowing you to choose to have LANnouncer respect the phone silence modes (or to ignore them; the default is to respect that if the ringer is off, LANnouncer should be quiet, so you have to switch this on tablets), and volume settings.