Examine source code of Submit to Grepless

{
  "name": "Submit to Grepless",
  "description": "",
  "version": "0.0.0.1",
  "manifest_version": 2,
  "browser_action": {
    "default_icon": "img/32.png",
    "default_title": "Submit to Grepless"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "icons": {
    "16": "img/16.png",
    "24": "img/24.png",
    "32": "img/32.png",
    "48": "img/48.png",
    "128": "img/128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "js/script.js"
      ]
    },
    {
      "matches": [
        "*://grepless.com/new-story"
      ],
      "js": [
        "js/grepless.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "http://*/*",
    "https://*/*"
  ]
}