The name Killer App Rx might be a bit of a misnomer. When I was developing a prototype video game in the early 2000's and asked legal counsel if there was an appropriate "warning" to place on the video game they recommended that I do not release a video game that has the potential to hurt someone.
This might seem like a bit of an odd concept that a video game could hurt someone. But there's a bit of particular issue in one particular case where high-rate flashing lights in television programs can trigger epileptic seizures. It's called Photosensitive Epilepsy (read a webMD article on it or an article from the Epilepsy Foundation).
An example of flashing lights causing seizures is an episode of Pokemon aired in Japan in 1997. It resulted in several hundred children being transported to hospitals. (A second article is available at CNN.)
I would like to encourage mobile app developers designing apps intended to improve health to avoid including elements to their apps that could cause harm to the users of the apps. Killer App Rx is really meant to mean a recipe to avoid apps that can injure people.
I'm personally interested in mobile apps that can optimize our body's immune system. In the specifics of balance of the immune system, hoping to strengthen parts of the immune system could be either beneficial or harmful depending on where the balance's defiency is. So an app should be designed to "return the system to optimal" rather than "strengthen it." However, any app that intends to affect our immune system could have negative effects, although hopefully not as damaging as inducing seizures. That said, we can't discount the possibility that apps could hurt us.
Apps can definitely agitate us or relax us. Apps are not universal in the effects they cause. Even apps intended to improve our well being or health would bore or even anger a significant chunk of its potential users. Competitive development of apps would lead better choices for users and could improve the chance that more users could find benefits from interacting with the apps.
We've already seen video games reduce pain in patients some studies. Some are merely distractions while others are designed to affect pain levels. I will be prototyping a mobile app codenamed "The BrrCebo" intended to make fighting the common cold less miserable, but its development will taken into account that anything intended to help someone could unintentionally harm someone and suspect groups should be warned of the potential harm.
Read my common and expanded thesis statements on digital immunostimulants.