I bought this gadget about a month ago. I have it attached to the tap in my bathroom, and I love it! It allows me to turn the bathroom tap into a cool, bubbly drinking fountain with the flick of a finger. To fit it on the tap I had to take the aerator off the end of the faucet, but I find I like the water better (both for washing and drinking) when it hasn’t passed through the aerator.
I have arthritis and my hands are weak, so instead of pinching the tapi to create the fountain I just fold the end of it over, and this works very well. I think it would be easy for a child to operate. It comes in a variety of colors, and only costs around $6.