Interfaces
Add-ons are separate applications that integrate with or extend Suntimes through the use of public interfaces. Add-ons may start intents, use content-providers, or implement content-provider contracts.
Add-ons must declare the READ_CALCULATOR permission. This permission is granted during installation.
See https://github.com/forrestguice/SuntimesWidget/wiki/Interfaces for a list of interfaces available to add-ons (and other applications).