title: What are the major challenges of building an iPhone application that synchronizes data with a server via web APIs?
body: <p>I want to build an application that utilizes the data from a server, and it needs to synchronize the data in the application with the data entered by other client applications.
  So, there are some questions:</p>
  
  <ul>
  <li>How to design the database schema efficiently? Should it replicate the same database schema  on the server or should it add some more fields &amp; entities?</li>
  <li>What are the strategies to synchronize the data, on each application start or during some idle state of the application, or something else...</li>
  <li>How to handle conflict of the data entered by the user within the application and data enter ed by another client application.</li>
  </ul>
  
  <p>Any response is welcomed.</p>