very good idea for tv input lag testing app

I dont know anything about android development but have good idea for anyone who wants to try.Today bigest problem when buying LED,LCD or PLASMA tv for gaming is input lag.Almost every new android smart phone have light sensor and can be conected with tv thru HDMI like my Galaxy s4.I have giving you an idea to make app for input lag testing on smart TV.You can buy Leo Bodnar lag tester for 120 dollars,but if someone make app for lag testing everyone can test TV in shop with android device before buying it.