app(name) returns firebase.app.App
Retrieves a Firebase app instance.
When called with no arguments, the default app is returned. When an app name is provided, the app corresponding to that name is returned.
An exception is thrown if the app being retrieved has not yet been initialized.
Optional name of the app to return. If no name is provided, the default is
non-null firebase.app.AppThe app corresponding to the provided app name. If no app name is provided, the default app is returned.
// Return the default app var app = firebase.app();
// Return a named app var otherApp = firebase.app("otherApp");