title: How to sync data between different devices
body: <p>I am planing to implement an app and I have come to a point where I don't know what is the best approach.</p>
  
  <p>Scenario:</p>
  
  <p>I have an app where I am making a todo list and I am adding 3 items. I use my phone for this.
  Then I take my tablet and want to continue adding another task. Then after a while I take my wife's phone and want to add 2 new tasks.</p>
  
  <p>Basically I want to have a very simple way of storing the tasks online and be able to sync it with the app. </p>
  
  <p>I am seeing two possible ways:</p>
  
  <ul>
  <li><p>have a web server with a database + web service calls. This has the disadvantage of having a host paid, learn some extra mysql + web service techniques. </p></li>
  <li><p>store somehow the data on cloud and allow the app by login to access an account which stores the file. I am thinking here at something like Google Drive / Dropbox. But I don't know how I would be able to sync only the updated values, not the whole file. Because I am thinking, if I store all the tasks into one file, each time I update the file, I'll need to upload it fully, which is not the best approach.</p></li>
  </ul>
  
  <p>I am open to any advices. What approach would you recommend ?</p>