Some people have found that it is possible to use a drop of water as a magnification device for their phone cameras. It is a good technique to try to photograph smaller objects that you want to photograph.
They aren't waterproof, so they were careful not to get water in any cracks. It's a clever method, but definitely not a convenient one, since you also have to make sure the water droplet does not jiggle. This is impossible if you are holding the camera with your hand.