The example application uses Play 2.5 and Eventuate(https://github.com/RBMHTechnology/eventuate) for event sourcing.
The events are written to a LevelDB log.
The application also implements a sample websocket to push all the trade messages to connected clients in json.
The app is deployed on heroku, you can access it here - http://play-eventsourcing.herokuapp.com/
Find more information read this blog post - https://kunalkanojia.github.io/blog/event-sourcing-part-1