Dutch researchers are developing a simple smartphone attachment that makes it ridiculously easy to measure the quality of water. All you have to do is point the tool at the water you want to measure. That’s it. Such a tool could allow citizens to see if their drinking water is contaminated, or help fisherman determine the quality of their catch. Once data on contaminated waters is amassed, scientists will be able to create a map to see where water is or isn’t polluted, which could help steer environmental policies on a national level.