I’ll just quote the site on this one:
During mealtime, operating the salt and pepper shakers wears us out. We have to lift the shaker and move it up-and-down, up-and-down, up-and-down… It’s tedious, it’s tiring, and often dangerous.
So their invention? Self-shaking salt and pepper shakers. Link via American Inventor Spot, who also had in the same post the best towel dispenser ever.