Yifanlu announced a few hours ago that HENkaku release 6 is right around the corner. This new version adds GPU overclocking, and is not publicly released yet.
This release is not on the official url yet. Instead, to get HENkaku release 6, point your browser to henkaku.stary2001.co.uk/ and click on the link. (Note: this url was officially suggested by Yifanlu so we believe it is safe).
Please report feedback in the source below. Yifanlu is also asking for people wanting to host this beta (for themselves or to share with others) to get the latest source on the official github and follow the instructions in the README.