Important Note: As of September 2018, Google has deprecated the adsenseformobileapps.com placement exclusion, rendering this script obsolete.
This script was built to ensure adsenseformobileapps.com is systematically excluded from display campaigns.
The only part of the script that needs to be modified is replacing 'Display' by what you identify display campaigns with:
// Your naming convention to identify display campaigns
var DISPLAY = 'Display'
You'll also want to schedule the script to run hourly.
While I realize that you could simply add adsenseformobileapps.com to your account placement exclusions (which can't be accessed through a script right now), this automates the process so you don't ever have to think about it.