Examine source code of Bitcoin Tracker

{
  "manifest_version": 2,
  "name": "Bitcoin Tracker",
  "homepage_url": "https://timleland.com/bitcoin-tracker-extension/",
  "version": "1.0.4",
  "icons": {
    "16": "media/icons/icon16.png",
    "48": "media/icons/icon48.png",
    "128": "media/icons/icon128.png"
  },
  "description": "Stay up to date on the latest prices of Bitcoin",
  "options_page": "options.html",
  "browser_action": {
    "default_icon": {
      "38": "media/icons/icon38.png"
    },
    "default_title": "Bitcoin Tracker",
    "default_popup": "popup.html"
  },
  "background": {
    "page": "background.html",
    "persistent": true
  },
  "permissions": [
    "alarms"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{aade5557-acc0-4451-b71f-631cf51e2cef}"
    }
  }
}