With the advent of mobile medical apps, the FDA is setting up guidelines and regulations to govern the use and implementation of these programs. Some of the apps can provide guidance on diagnosing and treating radiation injruies, others can diagnose cancer or heart abnormalities, and some are glucose meters that can track insulin levels for diabetic patients. The FDA will only monitor apps that fall into one of two categories: 1) it is intended to be used as an accessory to a regulated medical device, or 2) transform a mobile phone into a regulated medical device. These apps obviously pose a greater risk to a patient's health if used improperly or if not regulated. There is also a greater risk for liability if certain apps are not regulated, since patients may rely on apps as medical advice when it should not be seen as such, thereby risking their health. The FDA created the Mobile Medical Applications Guideline in September 2013, explaining the regulation of health apps and which apps are subject to such regulation. Estimates state that 500 million smartphone users will be using a healthcare application worldwide by 2015. The FDA is encouraging the creation of these apps, in an effort to improve health care and allow greater access to health information.