Examine source code of Context Plus

{
  "manifest_version": 2,
  "name": "Context Plus",
  "version": "0.6.1resigned1",
  "applications": {
    "gecko": {
      "id": "{bb682c45-3136-4213-bf29-5f5833080bf4}",
      "strict_min_version": "57.0"
    }
  },
  "description": "Add a bunch of extra stuff to contextual identity features",
  "icons": {
    "48": "icons/browsers-64.png",
    "96": "icons/browsers-128.png"
  },
  "background": {
    "scripts": [
      "contextPlus.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "permissions": [
    "contextMenus",
    "contextualIdentities",
    "cookies",
    "storage",
    "tabs"
  ]
}