Examine source code of Tracked for Basecamp

{
  "short_name": "Tracked",
  "name": "Tracked for Basecamp",
  "version": "1.11.2",
  "manifest_version": 2,
  "description": "Kanban boards within Basecamp",
  "icons": {
    "48": "images/tracked_new_logo.png"
  },
  "permissions": [
    "identity",
    "cookies",
    "storage",
    "activeTab",
    "tabs",
    "https://www.trackedhq.com/*",
    "https://3.basecamp.com/*"
  ],
  "background": {
    "scripts": [
      "browser-polyfill.min.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "css": [
        "select2.min.css"
      ],
      "js": [
        "browser-polyfill.min.js",
        "content.js",
        "js/jquery.js",
        "js/chart-min.js",
        "select2.min.js",
        "js/chart-colors.js",
        "js/jquery-ui.min.js",
        "js/profiles/tracked_request.js",
        "js/options.js",
        "js/profiles/projects_builder.js",
        "js/profiles/board_builder.js",
        "js/profiles/tracked_api.js",
        "js/profiles/user_board_builder.js",
        "js/profiles/user_board.js",
        "js/profiles/default_labels.js",
        "js/profiles/default_lists.js",
        "js/profiles/master_board.js",
        "js/profiles/projects.js",
        "js/profiles/estimates.js",
        "js/profiles/new_todo_label.js",
        "js/profiles/basecamp3.js",
        "js/profiles/basecamp_labels.js",
        "js/profiles/tracked_home.js",
        "js/profiles/reports_dashboard.js",
        "js/profiles/tracked_admin.js",
        "js/profiles/mutation_observer.js",
        "js/profiles/completion_chart.js",
        "js/profiles/cumulative_flow_chart.js"
      ],
      "matches": [
        "https://3.basecamp.com/*"
      ],
      "all_frames": true
    }
  ],
  "browser_action": {
    "default_icon": "images/tracked_new_logo.png",
    "default_popup": "html/popup.html"
  },
  "web_accessible_resources": [
    "html/*",
    "html_js/*"
  ],
  "applications": {
    "gecko": {
      "id": "support@trackhq.com"
    }
  }
}