Lots of patients -- even patients taking life-saving medication -- are not as "adherent" as they should be, which means that the treatment does not work as advertised and drug companies lose money. There have been many attempts by the drug industry to improve medication adherence, but it has been a tough challenge. The industry, however, has not given up. The new battleground for combating non-adherence is the mobile smartphone and the smartphone app is the weapon of choice. Are the benefits worth the risk?