No apps can cure or prevent diseases. If one needs medical help help than a doctor is what they need. We should be very careful about our health. If we feel the need, then a professional medical advice from a doctor should be sought. 

Many advertisements for apps and devices are made in the market that suggest that they might help during a disease, Please bear in mind that these apps can assist you with the timings for diet and medication. They can also assist you in getting in contact with the hospital in case of emergency. 

Beyond that, you are yourself responsible for your own health.