The Replay Viewer is in early beta and currently has limited functionality. We'll be adding more features and have plans to use them for advanced match statistics in the future.
The Advanced Match Tracker is an application you can run locally on your computer to automatically upload replays to Fortnite Black after your game has finished.
Our intention with this is to provide Fortnite Black with data for more advanced match breakdowns, for both you and other players in your matches.
Advanced Match Tracker is currently in private beta. But we aim to release it publicly as soon as possible.
Due to Stats V2 it will take us a bit longer to release this publicly.