There's a new version of the Embedded Host Client Fling available. I downloaded the offline bundle of the VIB, imported it into VUM and pushed it to my ESXi.
Just open ESX-HOSTNAME/ui/, enter the credentials and you will get into an interface that is similar vSphere Web-Client:
As William Lam already pointed out, it's possible to edit the disk's partition table. That's very handy while testing VSAN!
(There seems to be a problem if you are using a non-English localization in your browser.)