Background fetch initiated via remote notification

App registers on quickblox, will receive a notification every 5 minutes, maximum 90 seconds after latest bgreading.
This notification will trigger an upload to NightScout

set transmitter id

• Initial and subsequent Calibration
• Additional calibration request alerts but not the 12-hour calibration request alert
• View latest calculated value on Home screen with "minutes ago" and diff with previous reading
• Always on notification (not really always but almost always) that allows to see the current value by just lifting up the phone.
• Synchronisation to Nightscout
  • When the app is in the foreground, upload will always happen immediately after receiving a new value, also at app start,
  • When the app is in the background, then it is iOS that decides when the app is allowed to do an upload. The frequency is very unpredictable, in fact it is not really usable.
• Set transmitter id

upload works, at least an hour, on iOS9

on iOS 10 there seems to be a crash

reuse nsurlsession object - seems to have solved all

see tag 0.0.15 ANE

5 successful uploads

see 0.0.14 of backgroundfetch ane

4 consecutive uploads

then it stopped