Scylla is Apache Cassandra compatible at the CQL binary protocol level, and any driver which uses CQL will work with Scylla (more here). Any application which uses a CQL driver will work with Scylla.
The list below contains integration projects using Scylla with Spark. If you have tested your application with Scylla and want to publish the results, contact us using the mailing list.
Analyzing flight delays with Scylla on top of Spark (blog entry)
Analyzing Data with Spark lesson on Scylla University