Real time is an excellent debugging tool. You can see what your users are doing in real time, if they experienced crashes, or some unexpected behavior. It's a great way to validate that production releases are working as expected, and how your app behaves for users that are of your interest. If your app has a freemium, and an enterprise customer is having trouble while uploading a document, you'll be able to easily debug it with this feature.
We define real time as a time window of 60 seconds from the time the last event happened. That means that if a user is interacting in any way with your app, you will be able to see it's activity until it goes inactive.
Note: there's a time window between the event happening, processing ourselves and showing it.