At the top of the Display Settings page, you can view and adjust the frequency your apps will play.
This section allows you to set the percentage of time that will be dedicated to each app. For example, if you have 4 apps all set to 25%, in a time period of 1 hour they will each play for a total of 15 minutes, randomly switching off every 90 seconds.
For more details on app frequencies and how apps rotate, please see our app rotation article.