This is an iPhone and Apple Watch application to display blood glucose values stored at your nightscout server.
This app displays the last 30 Values from your [nightscout] (http://www.nightscout.info) [server] (https://github.com/nightscout/cgm-remote-monitor):
A graphical representation is shown on the Apple Watch as well:
The dark gray region in the chart marks the values that are between 80 and 180.
This small video shows how to check the configuration and demonstrates the available Apple Watch Complication: http://youtu.be/CEcqNyyv_kA