Glucomate request access to HealthKit data from your mobile device to function correctly. Blood glucose data is required to use the app properly, as the purpose of the app is to display blood glucose data, history and trends over time. Sleep and workout data access is also requested. Glucomate uses this data to show your blood glucose during sleep and during workouts. This access is optional. Without it, some features are not available. If access to any HealthKit data type is denied, Glucomate has no way of reading this data. At any time the user can choose to restrict Glucomate's access to any HealthKit data type. If Glucomate is denied access, it has no way of viewing this data. Glucomate does not capture or store this data anywhere even when access is granted, so revoking permissions is enough to ensure Glucomate has no access to any of your Health data.
When you change or modify a preference or setting in Glucomate, this preference is stored locally on your device so that the app remembers it the next time it is launched. This data is stored locally, and some preferences may also be shared between devices - e.g. between your iPhone and Apple Watch.
If you have any questions, or would like to clarify something, feel free to get in touch through this link.