We are creating homebrew books with different themes. Our first one and soon to be released is a spellbook for wizards and sorcerers with interesting twists, unique spells and mechanics, and a hidden story between all the spells as well as a cool NPC to be introduced in to your campaign. In the future we will create spellbooks for the rest of the classes.
Another thing we are working on is a book about mimics containing all sorts of information about them, a way to create your own custom mimic and a one shot adventure centered around it.
Without revealing everything, these are just a few of the projects we are working, so stay tuned.