read
Add this permission to the list to the file “packager.json”:
<pre style="background-image: URL(http://2.bp.blogspot.com/_z5ltvMQPaa8/SjJXr_U2YBI/AAAAAAAAAAM/46OqEP32CJ8/s320/codebg.gif); background: #f0f0f0; border: 1px dashed #CCCCCC; color: black; font-family: arial; font-size: 12px; height: auto; line-height: 20px; overflow: auto; padding: 0px; text-align: left; width: 99%;"> WRITE_EXTERNAL_STORAGE
</pre>
Note: if you are using Sencha Architect you should have to edit the file with gedit or other text editor manually before build your application because Sencha Architect rewrite this file every time you save.