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.
Open CGN in one window and your picture host site in another then on the CGN toolbar click on the "insert image" box and copy/paste the URL of the picture.
FWIW, I use flickr. works well and is simple to use.
