Examine source code of Linkpack

{
  "name": "Linkpack",
  "author": "Evil Window Dog",
  "version": "1.4",
  "description": "Linkpack extension for Firefox",
  "homepage_url": "https://www.linkpack.io",
  "manifest_version": 2,
  "icons": {
    "256": "icons/icon256.png"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+Shift+L"
      }
    }
  },
  "background": {
    "scripts": [
      "js/dropbox-sdk.min.js",
      "js/events.js"
    ],
    "persistent": true
  },
  "options_ui": {
    "browser_style": false,
    "page": "html/options.html"
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon76.png"
    },
    "default_title": "Linkpack"
  },
  "permissions": [
    "tabs",
    "storage",
    "notifications",
    "contextMenus",
    "history",
    "webRequest",
    "http://*/*",
    "https://*/*"
  ],
  "web_accessible_resources": [
    "html/chrome_oauth_receiver.html",
    "css/content-style.css",
    "images/folder@2x.png",
    "icons/action_cancel.png"
  ],
  "applications": {
    "gecko": {
      "id": "temporary@linkpack.io"
    }
  }
}