title: Best way to use one File in multiple apk
body: <p>I develope few applications that need to read and write to the same file in order to present the user his progress on all apps from each single application (Something like shared history of different tasks or achievements).
  I try to write on external directory but I I don't know if this is the best solution for me because I can't implement it on all devices.</p>
  
  <p>Any suggestions?</p>