I’ve seen a couple people using water on the lens of their iPhone for macro shots. I set aside my fear of destroying my phone with water and gave it a shot. The results weren’t perfect, but some of the shots are very useable and impressive considering it doesn’t cost a thing. I found that having just a little bit of water on the lens was better than having a larger drop hanging and jiggling around with every slight movement. If you’re going to try this out yourself, you have to get extremely close to your subjects before they start to come into focus.
The first image is an unripe strawberry and the second is a ranunculus from the garden.