Hi @marwan17705
marker value is wrong. It is always "general marker".
In fact there is one or two notifications for each measurement, depending on the fact that there is or not a "mark".

Here are some details:
first byte:
bit 0: Time Offset Present (bool)
bit 1: Glucose Concentration, Type and Sample Location Present (bool)
bit 2: Glucose Concentration Units (0:kg/L , 1:mol/L)
bit 3: Sensor Status Annunciation Present (bool)
bit 4: Context Information Follows (bool)
bits 5-7: Reserved for future use

You can see that bit 4 tells if there's a "marker" notification or not.

All details for all services are here:
https://github.com/oesmith/gatt-xml/blob/master/org.bluetooth.service.glucose.xml

Good job!
It would be nice if one could choose begin and end date for the graph.

Also, to avoid pairing every time, you can hardcode the pin code. It is given in the user manual, so there's no security risk.