A forum post [Google English] announces the availability of the beta version of MultiWindow Android for the Chuwi V88. Oddly, it mentions the V88s too — which has just 1GB of RAM.
This is the download direct link (Chinese-language file-sharing site). It’s a 274.24MB download. However, instead of going to that link, go to Chuwi’s actual site [Google English], where it’s the top link. (Note that you might have to use the Chinese-language site directly for downloading.) There is no mention of this being for the V88s at Chuwi’s site.
Since this is just a beta, I’d advise waiting for the final upgrade from Chuwi itself.