Examine source code of Linkkeeper

{
  "manifest_version": 2,
  "name": "Linkkeeper",
  "version": "1.2",
  "description": "Keep links",
  "background": {
    "scripts": [
      "keep.js"
    ]
  },
  "permissions": [
    "menus",
    "activeTab",
    "contextMenus",
    "storage"
  ],
  "icons": {
    "48": "icon.svg",
    "98": "icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "linkkeep@aland.com",
      "strict_min_version": "55.0"
    }
  }
}