I am currently testing a new feature that will enable registered users to receive email notifications when new content it posted to this site.
The main control panel for this can be found on your account page. From there you can view and edit your current subscriptions, subscribe to specific types of content and edit your preferences.
You can also subscribe to specific pages directly from the page itself. This might be useful if you only want to receive notifications of updates or comments for selected items (be it an app or a guide).
If all goes well with the testing, this should provide an additional means of following activity on this site (along with Twitter and the RSS feeds).