It will not be possible to keep mobile Display ads from showing on apps. There are fine tuning options to control what kinds of apps ads show in.

Please visit Search Engine Land for the full article.

http://feeds.searchengineland.com/~r/searchengineland/~3/1gETBdgYikU/action-needed-if-youre-using-adsenseformobileapps-com-to-exclude-apps-from-google-display-campaigns-303080