Examine source code of Inline Downloader

{
  "manifest_version": 2,
  "name": "Inline Downloader",
  "version": "1.0",
  "description": "Adds a download button to media elements (images, video, audio) directly on the page.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/icon-64.png",
    "default_title": "Inline Downloader",
    "default_popup": "popup.html"
  },
  "icons": {
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{73686cff-209c-4ba3-9252-cb75c4d36a34}",
      "strict_min_version": "89.0"
    }
  }
}