Push notifications and the app
Your board can behave like an app: members can install it on their phone's home screen, and it can send real push notifications that arrive even when the board isn't open. Both live in Configuration, then Settings, on the App & Analytics tab.
Push notifications
With push enabled, members who opt in get notified about the things that matter to them, mentions, replies, private messages, without keeping a tab open. Each member chooses for themselves; you're switching on the capability, not signing anyone up. The browser asks them for permission the way it does for any site, and they can withdraw it at any time.
The install prompt
The second switch invites visitors on phones to add your board to their home screen. Installed, your board opens full screen with its own icon, your favicon, and feels like a native app. It costs your members nothing and makes daily visits one tap instead of a typed address.
Both features work through the modern web, no app store involved. There's nothing to submit, review or update; your board simply is the app.
Set your favicon before turning on the install prompt (Configuration, then Settings, on the General tab). It becomes your app icon, and a default icon on someone's home screen is a missed opportunity.