[Android Central Question]

The idea is simple place the phone at where you usually sit and watch TV with the camera facing the TV. The phone microphone will listen for an audio cue like short duration beep with visual cue like a bright red color. Then the app will show the value in miliseconds (negative or positive) of the discrepancy in time between audio and video cue.

[Rukbat]

I very much doubt that anyone will even attempt to develop an app like that.