While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
I'm never found the answer if one was ever made as 336's weren't D&T'd pre 56 I believe. I heard of people going th easier route and swapping the hammer out to a post-57 and just using the post-57 spur.