An App that knows how you feel by reading the expression of your face

I was "surfing" my favorite sites and I found this interesting video to start a good debate: What if digital devices are able to read face expressions and react to them? 

There's a global discussion saying that Technology is doing a disservice to our relationships, because we're losing the emotional component... This scientist has developed an App that can read the faces and interprete the emotions in real time. What to you think? I leave you the link to the video of TED Talks: http://goo.gl/NNDQdb