I think it would be nice to have an app to:
- allow person to select quickly and easily a set of symptomes that he/she feels.
- Upon submission the app would send notification to person's doctor as well as search world's databases for possible diagnosis.
This way your dad would get an immediate feedback on his screen: "POSSIBLE STROKE! URGENTLY CONTACT YOUR DOCTOR", allowing him or his loved one to apply extra pressure to medical professionals.