Ending in about a month, Sparkathon is a really cool hackathon to write innovative applications for Apache Spark running on IBM's CloudFoundry-based PaaS, BlueMix. It's sponsored by IBM and promoted in partnership with Typesafe, NYC Data Science Academy and Urthecast.
I have registered and the nice feature is you get a free IBM BlueMix trial account and access to cool weather data while you are working on it. It includes access to Analytics for Spark as a trial.
I have just started on a Spark application that will have a Spring Cloud/Spring Boot front-end also hosted on BlueMix.
If you have interests in big data, cloud, PaaS, Spark or the like, sign up and give it a try. It's a great free learning experience and hackathons are a lot of fun. See if your friends, coworkers want to join up.
There's a well documented use case of Twitter Sentiment analysis on IBM's site to help you get started: