This is an app that’s designed to help conquer depression, and I don’t use the word design loosely. My conversations with the folks behind the app at BrainTracer lead me to believe that they really know what they’re talking about, and some of what’s going on behind the scenes is fascinating. But the real question is: How is an app like Moodtune going to help you? And can it help you? Will you want to use the app enough to turn it into a healthy habit?