Wouldn't that be easily fooled by just pressing the pill against your abdomen for a while, and then throwing it away? Or sticking it with a piece of duct tape?
Seems like this solutions kind of assumes that all pshychiatric patients are stupid.
It would be difficult to game this but it is still possible. The app itself could be broken for example.
I think the FDA approval for this device assumes the patient actually takes the medicine so no guarantees are made if the patient doesn't.
To tie this to my point, adding in electronic reporting and measuring opens up a number of possible ways of getting false data during a trial so I think it would be difficult to manage that. For example, in oncology trials, monitoring for adverse events and cancer progression might involve blood draws for analysis and maybe a monthly progression scan. These types of things are much easier controlled at a central location. Although not all trials are the same and electronic monitoring and reporting seems to have a lot of potential for drug usage and trials.