My scenario is control iphone music player on applewatch. Just like what the applewatch music glance would do. The project is gonna be iphone app, watch app, and watch extension. however, I want it to be able to work even thou my iphone app is not active. I know when iphone app is active, I could use wcsession and sendMessage to control the music on iphone. However, when the iphone app is not active. I don't know what I should do to get the work done.
One more thing, I don't understand how iphone app works when it is not active. Does it need to be active first do those job, or it is never really inactive so it could still do work?