There’s a small group on DeviantArt that might be of interest to anyone who uses that site and writes; Adopt a Plot.
If you’ve got an idea you can’t do justice to, toss it in there. If you’re looking for an idea for a stray character, plot, or setting, poke around. Everything here is freely offered, from resources to image textures to hopefully helpful critique.
Yes, free. The group creators and mods have Issues with the whole trend of Adoptable artworks for sale – especially since various artists keep trying to swamp the group posting their for-sale works despite its explicit guidelines that this is for writing. And not for money. The mods finally had to slam various requirements on who can join the group to make people quit that, so if you want to officially be part of the group rather than just read and lurk you’ll need to apply. Just so you know.
Things the group mods want to see shared: Plots, character development, setting development, world-building notes, and any notes and preliminary work that might be useful to writers in need of inspiration.
They also submit and accept typography, writing resources, cover resources, and links to all of those plus virus-proof software, useful blogs, forums and online communities.
In case this turns out useful for anyone. 🙂