Examine source code of harmonoid-js

{
  "name": "harmonoid-js",
  "description": "Harmonoid extension for playing music",
  "version": "1.0.2",
  "permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "author": "harmonoid",
  "icons": {
    "128": "assets/icons/128.png"
  },
  "browser_action": {
    "default_popup": "index.html"
  },
  "web_accessible_resources": [
    "assets/*"
  ],
  "manifest_version": 2
}