Apps that are installed from the Play Store while the device is armed automatically get uninstalled when the device has been left in idle mode for more than 1 minute.
To install apps that will not get removed from the device, the Display app must be disarmed during the installation process.
To disarm the device, tap 5 times in the bottom right corner of the screen, while a campaign is playing, and enter the security PIN.
Display for Android 7 - Add-on Guide | RTF-SC-0196 | Rev. 4