When you work in a client side application, you always wait for something to happen, an event. This isn’t happening only in Android, in every client side application I’ve worked (regardless of technology) you always wait for the user’s input. It could be a button click or something else, but that’s the whole meaning of interactive apps. It makes sense then to design your code structure based on this principle, you always wait for an event. It also makes sense to keep the event communication happening through a single object, otherwise your code can become a nice ball of spaghetti really fast! The Otto event bus can be that object for you.
In a world where HTML5 is advertised as the solution to every problem, someone would think that you will need nothing more to create a web app based on data and media. Unfortunately the reality is somewhat different. Stream Pod is a fine example of such an application, it’s an audio player which is based on your search terms to find what it will play. The audio player in Stream Pod is using Flash as the core technology and the reason for this decision was the need for fast development without a lot of browser headaches. There is some great work being done with media in the HTML5 world but personally I would use it as a fallback to Flash for these use cases at the moment.