However, manual adjustment /calibration can be time-consuming, lack uniform measure, and tricky. Because human eyes are good at adapting to the environment, in many scenarios, people can not be sure if it is the same color that they picked the last time precisely. On the other hand, purchasing dedicated calibration hardware requires extra expenses and waiting time and can cost more than a high-spec display. To save your time and multi-path attempts, we introduce CalibCat as a fast auto-calibration solution, in which we bring state-of-the-art research results and provide affordable schemes for the general public. Now what you need is a quality-assured camera, but wait, you already got one on your iPhone/iPad, right? If so, let CalibCat do the remaining dirty work! Before installing the app, make sure you have 1) a functional camera on the iPhone/iPad and 2) a counter-part desktop software (CalibCat Display).