Overpriced and Underwhelmed
The price is absurd for the level and amount of content. If you are not familiar with body language at all, I could see the application being used as an easy introduction... (And even then, the $3.99 price tag is egregiously high for what it provides). Much of the content, however, is common sense and offers no further insight than any source you can view for free via a Google or a YouTube search.