Examine source code of AddToOmniFocus2

{
  "manifest_version": 2,
  "name": "AddToOmniFocus2",
  "version": "0.2resigned1",
  "description": "Add To OmniFocus2 Firefox Extension (Unofficial)",
  "homepage_url": "https://github.com/jbking/AddToOmniFocus2",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/icon-32.png",
    "default_title": "Add page to OmniFocus"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5b4d309c-173a-4254-821d-afb07311bd78}"
    }
  }
}