LiiBook has been open for close to a year now. It was launched by Federico Roma, a 30-year-old native of Argentina. As you can probably guess from the founder, the site does lean heavily towards Spanish language content. But it does also have a fair amount of works in English, too.
This site has some details in common with Feedbooks, in that it is designed to help authors release individual works. But it's also different from Feedbooks because LiiBook is designed to support short works - in particular, ones that don't necessarily have any commercial value. Writers are encouraged to upload any completed work, whether its a short story, book, or even a poem. There are actually a number of poems (both short and long) on the site as well as quite a few short stories. On most sites you would see the shorter works bundled into a volumes, but on LiiBook authors are encouraged to post them one at a time.
Authors have the option of giving away their work, but they can also sell it. They can set the price in credits (currently valued at $1 each). Users can purchase the credits, and authors can redeem the credits via Paypal.
You can read the free works online, and you can also download them (registration required). The ebooks are DRM free and you can download them as PDF, Epub, and Kindle.
As for posting your work, the upload page looks to be well designed for short works. Everything fits in a single page, and there doesn't appear to be an option for uploading and assembling chapters (you can do this on Feedbooks).
All in all, this could be an interesting place to hang your hat. An author would still need to promote works elsewhere; this site isn't widely known. But it functions smoothly and is pleasantly designed, and that offers some value.