During World War Hate, a magic spell caused the inversion of Tony Stark's moral axis. The new egocentric and determined Tony Stark released a modified Extremis 3.0 to San Francisco, giving the people the option of physical perfection. Stark initially released the app for free in order to induce dependency before eventually revealing it was only a trial run, and the continuous use of it required its user to pay $99.99 daily.
Daredevil later discovered the truth behind the Extremis app, and confronted Tony about it. Stark prevented Murdock from acting on this discovery by inflicting minor brain damage that would erase Matt's memory of this revelation, and also intended to reprogram Extremis to be activated by a signal that Murdock couldn't detect.
The Extremis 3.0 App allegedly allowed its user to download the 3.0 version of the Extremis virus into their body in order to gain the perfect body. In reality, the Extremis virus was already present in the body of any of its potential users, since Tony had contaminated the water supply of the city with it. All the app did was to serve as a trigger for the effects of Extremis through a subsonic frequency.