title: Is it possible to run an Android app without onStart()?
body: <p>I am totally new to Android and I'm just learning about the Activity life cycle.<br>
  In all the apps that I have made so far to practice, I hadn't been using the <code>onStart()</code> method (mostly because I didn't know of it) and the apps worked perfectly fine. </p>
  
  <p>Why though did they work perfectly fine?<br>
  And when do I have to explicitly write an <code>onStart()</code> method in my app then?</p>