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.
As far as I know, it's to drain any water that gets in there through the receiver, and it will also stop any hydraulic effect caused by grease/lube sealing the space between the buffer and the tube.
