To control your Spark, Spark MINI, Spark GO, Spark NEO, and Spark NEO Core, you'll need to pair the Spark Control X with the Spark app. However, if you're using Spark LIVE, Spark EDGE, and Spark 2, the Spark Control X functions as a standalone foot controller, allowing you to connect directly to your Spark LIVE or adjust settings through the app.
See also:
How to connect Spark Control X to the Spark 40 / MINI / GO / NEO / NEO Core?