On the bottom bar of your app, you'll see a tab that says 'PRO'. From there, click 'DISCOVER' at the top of the page.
There, you will see a list of systems that will be sorted by the number of current picks. You can also click on the three-bar symbol in the top right corner of the page to filter which sport you are looking for.
When you see a system you like, click on it to see a more detailed description. From there, click "ADD TO MY SYSTEMS" to receive plays and alerts on system matches.