Meet Daisy.si: a smart plant watering system that uses sensors to take better care of your plants. It has a soil moisture sensor, a light sensor, and an advanced water dosing valve. You also get a LED light to show soil moisture content. You just need to bring your water container to get started.
Daisy.si makes sure your plants are watered adequately. You can adjust its settings from your smartphone, tablet, or computer. Users can sets the upper and lower limit of humidity and the amount of water. Of course, you can rely on the algorithm these guys have developed for the job.
Daisy.si alerts you when the water tank is empty. It is OS independent. The project is on Indiegogo.