Even if you’re not exactly green-minded, cutting down on your water usage can save you a ton of money, which just about everyone is into. Unfortunately, a lot of the gadgets that can help you save water at home – like low-flow toilets and showers – are also kind of a pain to install and use. The Waterpebble strikes a balance between being helpful and being unobtrusive while appealing to our competitive nature.

The gadget is just a little plastic gizmo that sits on the bottom of your shower while you’re sudsing up. The first time you use it, the Waterpebble measures the amount of water you use. On every subsequent shower, the Waterpebble continues to measure your water consumption and compares your usage during this shower to that from your first shower. The gadget starts out glowing green, then when you’ve used half as much water as your first shower it turns yellow. And when you’ve reached the same amount of water consumption as your previous shower the pebble turns red, letting you know that you’re going over your self-set time limit.

With each shower, the allowed time gets just a little shorter. Because the Waterpebble helps you gradually cut down your water usage, it’s not a huge shock to your system. Making that small change little by little every day is far easier than installing a shower head that never seems to produce enough water pressure to wash the last bit of shampoo out. Competing against yourself or others in your household is enough motivation to keep trying to improve shower times every day.