I built one for my DD from the ana.white.com plans.
She is 3yrs and 4 months now. I built it about 2 years ago.
We still get lots of use from it. She can now get up in it and use the sink to wash her own hands and face before and after meals.
She also likes to help rinse the dishes. And we use it to let her help bake and cook. Which at 3 she is of more help now than before.
We also use it to hang the dish drying cloth on...and other misc. things.