Please use a more descriptive variable name. What is "manager" what is it managing? Is it the plugin manager?

I don't think FreeseerApp is the best place to hook the notification system in. FreeseerApp is a base class that configures common items for Applications that inherit it to use. I think Notifications only make sense in the Recording app. Otherwise TalkEditor and Configuration Tool will also get a notification system which I don't think they need.