You could check out an open source chat application (both front and back end) I am working on in my spare time to get practice with and demo akka, including akka-cluster, persistence, sharding, http, streams, and (eventually) websockets. The code base is still quite small and not all the pieces are in place, even so it is a working app; it would be a great opportunity for learning the application of the various akka technologies.
As more people get involved with the project, it will also benefit other developers who are getting up to speed with the akka toolkit.
If this is of interest, then hopefully the README is enough to get oriented, but feel free to ask questions.
good luck,
Eric