How much joyful life u can lead, it depends on how much healthy you are. Some really facilitative and useful apps of iPhone can make easier and effective of all physical processes to maintain your health is good in all cases. Those apps are iTriage, WebMD Mobile, Workout Trainer, Strava Cycling, DailyBurn.
Note: Please don’t it as replacement of doctor. If you feel something sick – don’t make mistake to consult with doctor.