From the comments: Health apps are about as effective as public health ads.

The problem with many apps, and health campaigns for that matter, is that they tend to see people as individual actors, who are solely responsible for their own health, while all of us live in a society in where so many decisions are made for us. In sociological terms, I would say that all I read about are so-called solutions on a micro level, and hardly ever on a meso or macro level.

As long as we expect people to make the healthy decision all by themselves, only the hyper motivated will succeed, while for most of us health priorities will just be added to that long list of things we have to do every day. Most people don’t live to be healthy, they want to be healthy to start living: health is a tool, not an aim by itself – while most apps expect their users to see health and healthy lifestyles as an aim by itself. As long as health is approached this way, individualizing people and not seeing them as part of a community, as economic consumers of a food industry, as citizens in a political environment, health interventions are bound to fail. 

Redesigned lab results, health games, etc won’t suffice and will only bring incremental changes, if we want behavior change, it will have to be facilitated on many, many levels.

From the comments: Health apps are about as effective as public health ads.