I've played with and written code for Android and I learned the concept of Intents and BroadcastReceivers in Android. They are used to call Apps for specific purposes like making a call or playing music or asking for enabling bluetooth. Apps can register for these Intents, which get usually "broadcasted" and then can handle them.
What is the proposed equivalent to that on the Ubuntu (freedesktop, whatever) platform? Specifically in the context of phone apps, but also for desktop apps.
First I would think of URI schema handlers, and than with more doubt, some DBus construct.