http://webintents.org/save image/* as Blob client

gistfile1.js

var i = new Intent({
  "action": "http://webintents.org/save",
  "type": "image/*",
  "data": blob
})

var onsuccess = function(data) {
  var img1 = document.getElementById("img1");
  img1.src = URL.createObjectURL(data);
};
var onerror = function(){ };

window.navigator.startActivity(i, onsuccess, onerror);