How does NVIDIA’s sync works with mobile?

I have heard a few days back that NVidia has launched G sync for mobiles. What is this Gsync technology? If this company has launched this lately for mobiles, then was it available previously for other devices too? If yes, then what type of devices comes under this category? How does Gsync works? What are the requirements for this new technology? How would I know that whether my mobile will be able to use this technology or not?
