Sit Mod

Sit is a simple mod with a simple function - it adds a mechanic which lets the player sit on stairs and half beds. With this mod installed, you can right click on the top surface of any stair block to sit on it. Once you sit on the stair, it'll appear as if the player is sitting on a chair. You can crouch to stand up again.

This is a Forge mod and download links are given below.