Examine source code of ExNicoExtension

{
  "icons": {
    "16": "icon16.plasmo.192fd1f9.png",
    "32": "icon32.plasmo.4d28be0c.png",
    "48": "icon48.plasmo.8337b32e.png",
    "64": "icon64.plasmo.c5fef9ed.png",
    "128": "icon128.plasmo.20a0583f.png"
  },
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "16": "icon16.plasmo.192fd1f9.png",
      "32": "icon32.plasmo.4d28be0c.png",
      "48": "icon48.plasmo.8337b32e.png",
      "64": "icon64.plasmo.c5fef9ed.png",
      "128": "icon128.plasmo.20a0583f.png"
    }
  },
  "version": "0.1.2",
  "author": "Negima1072",
  "name": "ExNicoExtension",
  "description": "Browser Extension of ExNicoWatch",
  "background": {
    "scripts": [
      "background.806a2724.js"
    ]
  },
  "permissions": [
    "cookies",
    "*://*.nicovideo.jp/*",
    "*://*.ex.n4a.dev/*",
    "*://*.dmc.nico/*",
    "*://*.nimg.jp/*"
  ],
  "externally_connectable": {
    "matches": [
      "*://*.ex.n4a.dev/*",
      "*://localhost/*"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{90234682-cc88-494d-960c-c5934eb8f42b}"
    }
  }
}