Things is a collection of many small and a few bigger items and features that I feel enhance the vanilla experience in a mostly non-intrusive way
Curios API is required for all 1.16.x versions
Trinkets API is required for all 1.17+ versions
Most items have minimalistic documentation in their tooltip, Patchouli is highly recommended however as there is a very fleshed out guide. You get this when first loading into a world, and can also make a new one by Right-Clicking Gleaming Ore with a book.
Quick Walkthrough of some of the more notable items:
The Displacement Tome is an item inspired by Warp Book and it's many clones that allows you to teleport to up to 8 locations and uses Ender Pearls as fuel.
It is very expensive in a semi-vanilla context, in bigger modpacks it would need to be balanced though
The Bater Wucket is an infinite water bucket. That's it
The Ender Pouch is a portable Ender Chest accessed through a Keybind
The Enchanted Wax Gland is inspired by Trinkets and Bauble's Stone of the Sea. It makes you float in water and also gives a great speed boost.
You can also combine with another item to even make it work in Lava!
A huge thanks to pois1xlive for providing the textures