Just don't forget that if people don't know how to find it, and are not attracted to it, they will never give it a go. The effort to attract people is a lot more then create the app.
I do believe though that an app is a necessity if we want to increase the amount of players. It's quite obvious that the possibility to play the game whenever and wherever you want is attractive.
+ most people are lazy. Even at home I can guarantee that people don't bother to turn on the computer / laptop if they have their tablet or smartphone nearby.
Anyway, app would be great. But if no one is willing / able to go all the way with the e-marketing stuff then it's not worth the effort (even though I'd like an app myself).
“Careful with that ego, you could knock somebody over."