The seat Improved component is added to any item that you want to enable animation on; specially furniture.
Adding Seat Component
Create an empty Child in the furniture(To be able to move the animation easily). Add component on child and select Seat improved script.
Seat Improved Properties
Animation: You can upload the animation you wish to play here.
Gender Specific Overrides
This is used to set specific animation for male and female avatars.
Animation male : Animation can be specific to Male Avatars only if it is added here.
Animation female : Animation can be specific to Female Avatars only if it is added here.
NPC : NPC can be placed on the furniture by dragging and dropping the Statue(NPC) in the scene here. To read more on how to create an NPC in scene refer to Statue.
Seat Improved video tutorial
To know more about seat improved watch the tutorial shown here