if you are using Android and you have recently updated the operating system, it is probably due to the new Android settings that kill processes running in the background unless you explicitly allow them under the power settings.
Anyway completely new version is expected to be released any day now, so I suggest that while you wait you open the app every morning to make sure it is running.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.