Creating custom, context-based alerts

[emcas]

Is it possible to (or has anyone already) created a clockface or app that sends custom, context-based alerts based on external sensors instead of alerts at a fixed-time interval? For instance alerting the user to take a survey every time the temperature increases 3 degrees F. 

[JonFitbit]

There isn't a way to receive notifications/alerts without polling from the watch itself. You'd need to periodically poll a backend webserver to check for new events, then you could vibrate the device and show a simulated event on device.  Use the messaging api from device to companion, then fetch() to your backend. https://dev.fitbit.com/build/guides/communications/messaging/