NIH director Francis Collins wrote an excellent article on the Scientific American Magazine: "The Real Promise of Mobile Health Apps". The last paragraph of the article articulates where Dr. Collins sees the most useful areas of mHealth apps:
I am convinced, however, that the real potential of mHealth lies with much more committed users, such as the children with type 1 diabetes who took part in a yearlong, case-control study of wireless technologies to monitor and manage blood glucose levels. That study, published in Diabetes Care, showed that youngsters who used the automated system had significantly better glycemic control and diabetes self-management skills than those who did not. Now that's an mHealth moment worth getting excited about.