You can control who sees activity for each game and app you use from the App Center. Click Your Apps from the left side menu and click Settings under the app you would like to edit settings for. In the Posts on your behalf section, you can adjust who sees posts from that app using the drop-down audience selector. You can also adjust your app privacy preferences in your App Settings by clicking Edit next to the app.
Apps can only publish stories to people within the audience you choose from the audience selector. If you choose to hide your app activity from certain people, then those people won’t be able to see your activity in their app ticker. If you choose Only Me from the audience selector, no one else will see stories about your interaction with that app.