Fewer than 0.01 percent of mobile apps will be financially successful by 2018, predicts Gartner

This seems expected, and not disturbing at all to me. 1.) Apps can be useful to a company or developers without making money (from generating buzz to more) and 2) free with in-app purchases is where all apps are headed. The later can still be financially viable. See games. (And yeah, where games go, most follow.)