An Errbit app is a place to collect error notifications from your external application deployments. Each one has a name and a unique API key that your notifiers can use to send notices to Errbit.
You may have many versions of an application running at a given time and some of them may be old enough that you no longer care about errors from those applications. If that's the case, set the LATEST APP VERSION field for your Errbit app, and Errbit will ignore notices from older application versions. Be sure your notifier is setting the context.version field in its notifications (see https://airbrake.io/docs/).