Examine source code of Easy Session Manager

{
  "manifest_version": 2,
  "name": "Easy Session Manager",
  "version": "0.2.3.7",
  "description": "Easy Session Manager allows you to manage your Firefox session by backing up or loading your saved sessions.",
  "browser_specific_settings": {
    "gecko": {
      "id": "sessionManager@itdominator.com",
      "strict_min_version": "79.0"
    }
  },
  "icons": {
    "48": "images/icons/sessionManager48x48.png",
    "96": "images/icons/sessionManager96x96.png",
    "512": "images/icons/sessionManager.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "unlimitedStorage"
  ],
  "background": {
    "scripts": [
      "scripts/listener.js"
    ]
  },
  "browser_action": {
    "default_icon": "images/icons/sessionManager.png",
    "default_title": "Easy Session Manager",
    "default_popup": "pages/sessionManager.html"
  }
}