Sorry, due to some reasons, the cast extension is currently not available in Google Play, and Google Play does not allow non-Google Play apps to be downloaded, so we are unable to provide you with a direct download link for the video cast extension at this time. If you do wish to try this feature you can contact the author’s email, and I will send you the extension download link via email.
To request a download link for the video casting addon, send an email to chengkai.me@gmail.com with “video casting addon” in the subject line.