Oh my god thank you so much kikass!!! I was just working on this, and getting a little bit stuck when I found your answer.
I had already been using CollectionFS with my web app so I didn’t want to change that. I used dropzonejs for my web app frontend but somehow didn’t work on cordova.
Pretty much copied/pasted your code to replace the cordova fronend, and worked perfectly!!! Thank you so much probably saved me hours here!! 
