Apps are funny things. They tend to provide narrow utility -- focusing intensely on one specific thing -- but once you get used to them, you wonder how you lived without them. Take this Awareness! app, for example: it gauges environmental noise levels, sets up a threshold, and then pipes in anything louder than that into your skull alongside your music. Reasons why you'd want that to happen include oncoming SUVs, mothers screaming because their babies are in peril (from oncoming SUVs), or something as benign as your teacher yelling at you for not paying attention in cl
