title: How to create my own custom file type containing an image or an audio file
body: <p>I want to find a way to save captured picture and recorded sound in custom file-type(s) then open them in my app. I don't want to other apps could open my files (for example gallery app don't open my pictures).</p>
  
  <p>Is there any way to encode and decode my files in my app for example by writing a string at end of files.</p>
  
  <p>Thanks</p>