Shows your future angel shifts in an app and on the homescreen
To get your engelsystem api key:
* go to https://engel.hackover.de/?p=users&action=view
* click on 'JSON Export'
* copy the part in the url behind 'key='
To write it to the badge:
* Connect to the python console on the badge
* run 'badge.nvs_set_str("engel", "key", API_KEY)' and replace API_KEY with your key