Examine source code of Epoch-Converter

{
  "manifest_version": 2,
  "name": "Epoch-Converter",
  "description": "This extension will add an unobtrusive Human-Readable time tag right next to any unix epoch timestamps in the editor.",
  "icons": {
    "120": "epoch_icon.png"
  },
  "version": "1.0.1",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "epoch_icon.png",
    "default_title": "Show Human-Readable Timestamps"
  }
}