The Google Developer video on voice actions states that it is possible to implement custom voice actions. The example given is:
Ok Google, Shazam this song
Evidently this is not one of the system voice actions (take a picture, set an alarm, etc). The link provided by the video points to the Custom Voice Actions page, which states:
For example, developers have implemented commands like "scan my receipt on Walmart"
or "watch trailer for Inception on Flixster."
However there doesn't appear to be any explanation of how to implement custom voice actions, and the page crypticly states that:
Note: We are not accepting requests for Custom Voice Actions.
Stay tuned to Voice Actions - Google Developers and +GoogleDevelopers for product updates.
Does this mean that custom voice actions are not possible at all - or perhaps they need to be specifically approved by Google?
I'd like to implement a custom voice action so I could say a custom phrase such as Ok Google, Foo Bar which would be picked up by my own activity. Is this possible?
Edit: This has to be performed when the app is not already running - just for clarification.