Health apps for well people - problematic or panacea?

Some apps have the potential to encourage healthier habits and are accessible to most people, argues Iltifat Husain, but Des Spence notes the lack of any evidence of effectiveness and the potential for encouraging unnecessary anxiety. Read more about in our head to head "Can healthy people benefit from health apps?" - http://www.bmj.com/content/350/bmj.h1887