Google is not perfect in other ways besides showing closed rooms. If an app had really accurate data, it would be useful to those who both travel and like to play. I imagine that is not a large enough market to financially support the effort required.OP wants accolades not real discussion from people who care. How difficult is it to Google a pool hall then call them to make sure they're open and not hosting a big league or something at the moment?
The problem with calling the room is that all too often you get an answer like, "I don't know about that. Jack comes in after dinner. Call then." But that does tell you not to go out of your way to visit.
I'm not sure what app features are needed (see above) but the following kinds of info would be good (and are in some of the current apps):
location
website
phone
hours
number, brand, and size of each kind of table
remarks on table condition
tournaments
leagues
foot, beverage
age restrictions
cost