Examine source code of pltr

{
  "manifest_version": 2,
  "name": "pltr",
  "version": "1.1.0",
  "description": "Get the reading progress of the page right on top of your screen",
  "author": "Varun Dey",
  "homepage_url": "https://github.com/varundey/pltr",
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "64": "images/icon64.png",
    "128": "images/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/pltr.js"
      ],
      "all_frames": false
    }
  ]
}