It's slightly specific to Preact in a couple cases to chop off bytes. There's an open issue to make unistore/preact and unistore/react and keep the core just createStore().
Interesting as a comparison. A couple days ago I whipped up this functional-reactive example on top of Preact (lightweight React replacement), might be of interest to people looking at this:
http://esnextb.in/?gist=ba28702c94e22d26e3bc