I'm pretty sure that the homescreen is actually launched via an intent, though. ...

shardling on April 4, 2013 | parent | context | favorite | on: Facebook Announces “Home”, A Homescreen Replacemen...

I'm pretty sure that the homescreen is actually launched via an intent, though. At least, if you have multiple homescreens installed it prompts you which one to launch through the same interface that intents use. (Until you set a default.)