Custom Things is a mod which allows the creation of custom items, blocks, achievements, and recipes via JSON files.
It was made to allow modpack creators to add their own special "custom things" to the game without a custom-made mod to do so.
Documentation on how to use the mod can be found at the Github Wiki.
If you find something you think is missing, make an issue on the tracker! I will be happy to look into adding it.
This mod REQUIRES EnderCore to run.