Examine source code of Send2Prowl2

{
  "name": "__MSG_extensionShortName__",
  "description": "__MSG_extensionDescription__",
  "manifest_version": 2,
  "version": "2.0.0",
  "developer": {
    "name": "Chris Marc Dailey (nitz)",
    "url": "https://github.com/cmdwtf/send2prowl2"
  },
  "icons": {
    "16": "icons/extension.svg",
    "19": "icons/extension.svg",
    "38": "icons/extension.svg",
    "48": "icons/extension.svg",
    "96": "icons/extension.svg",
    "128": "icons/extension.svg"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "page_action": {
    "default_icon": "icons/send-to-device.svg",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e3847b59-ebfd-4b15-8b74-83465f8ffc3d}"
    }
  },
  "options_ui": {
    "page": "html/options.html"
  },
  "permissions": [
    "activeTab",
    "bookmarks",
    "contextMenus",
    "notifications",
    "storage",
    "tabs",
    "webRequest",
    "*://api.prowlapp.com/*"
  ],
  "default_locale": "en"
}