Broadcast for x-callback-url library updates released the Broadcast feature today, where users can create and subscribe to channels and get real-time push notifications when content is published in the channel. You need the Passport app to receive notifications and, of course, an account. Since the x-callback-url library has no RSS feed, there's not a direct way to be informed when a new app is included in it. Until now.

Keep your Passport in hands and subscribe to the x-callback-library channel for the latest apps added to the library. You can also follow me on Twitter to receive updates.