AQUACARE represents an elegant smartphone add-on and application for water analysis. Test your tap water and stop buying expensive carbon filters and bottled water. You wish to save natural resources? Map the quality of the water in lakes and springs, share your findings with society and help to localise water polluters. Give fresh water to your ornamental fish by monitoring water quality every day. Keep your swimming pool maintained by monitoring the pH and chlorine. AQUACARE is made of hard plastic; it uses lensless optics; there are no electronics and batteries. It allows you to backup and share your measurements between multiple smart devices and among friends.