Astrospheric's primary weather data comes from the Canadian RDPS model. This model covers The US (excluding Hawaii), Canada, and partial coverage of Mexico and a few other locations. Astrospheric further shrinks the RDPS domain for performance optimization.
Astrospheric's full domain can be seen in this image
If a forecast is requested outside of this domain then an error will be returned to the client. Greenland is partially covered, however an error may be returned if requesting a location in Greenland.
The Astrospheric app is available in Canada and the United States for iOS/iPadOS and Android. App stores do not allow exclusion at sub country level (state or territory), so information about Hawaii being excluded is in the app description.
Please note that Astrospheric has no influence over the domain covered by the RDPS model. Additionally, there are no plans to use any other model as the primary data source on Astrospheric.
Astrospheric's Cloud Ensemble uses data from other models which have different domains. More information about the Cloud Ensemble can be found here.