hmm for that I don't need a list. freehoster.ch allows many diffrerent subdomains. You can make with 1 accound 100 projects (no need to register and register over again).
I still recommend anyone who is serious enough about their online business or venture to avoid using free web hosting regardless how good they claimed to be. Most of free hosting company has one way or another of limitation which will cause many issue later. The worst of them is stability. They cannot give you enough stability even your website has a low volume of visitors, sometime cannot even give you a back up support. Too bad to rely on.
I'd not trust free web hosts and would better pay some dollars to see my web sites up and running fast.