SeriesGuide Extensions API
When viewing an episode or movie, extensions display an action button.
The button might link to external content (app deep-link, web page, ...) or trigger an action in another app (play, record, ...). Or it can just display some status information (such as "downloaded").
Add or remove an extension
When viewing an episode or movie, scroll to the bottom and tap Customize extensions.
Search the Google Play store for third-party extensions.
There is a getting started guide and example app available to learn how to build an extension for SeriesGuide.
Take a look at the API reference documentation.