title: Android application architecture - what is the suggested model?
body: <p>In the same way a web or desktop app might have three or n tiers - UI, Business, Data for example - what is the suggested structure for an Android application? How do you group classes together, what layers do you have etc? </p>
  
  <p>I'm just starting Android dev (an internet-based app that must respond to incoming notifications) and have no real feel for the structure I'm aiming at. Suggestions appreciated.</p>