Is it possible to stop certain apps from updating via Google Play?
I am not sure if you don't want auto update or you if you want to remove it from the update all list. All apps will appear in the update all apps list. You can not remove them from that list.

To remove from auto update go to Google Play Store &gt; Find the app you don't want to auto update &gt; Select the 3 dots on the top right of the screen and deselect auto updates.