: A detailed session on interpreting concealed thoughts and feelings through quick facial movements.
A web-based app with a that teaches recognition of emotions through micro and "mini" facial expressions based on FACS. Micro Expressions (iOS) Mobile Training
He learned to spot the subtle difference between a "social smile" (mouth only) and a "Duchenne smile" (eyes engaged). He learned that a unilateral lip raise was the universal sign of contempt—the "sneer" that had cost him the previous deal.
If you are a data scientist or a serious hobbyist, the most powerful free tool isn't an app—it's software development kit (SDK) called .