Examine source code of Jobr Plus

{
  "manifest_version": 2,
  "name": "Jobr Plus",
  "version": "1.2.0",
  "description": "Improves the UX of the Jobr interface for time entry.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.jobr.mobi/*"
      ],
      "js": [
        "content/jobr-plus.js"
      ]
    }
  ],
  "page_action": {
    "default_icon": {
      "19": "icons/icon-19.png",
      "38": "icons/icon-38.png"
    },
    "default_title": "Jobr Plus",
    "default_popup": "popup/index.html",
    "show_matches": [
      "*://*.jobr.mobi/*"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{25383326-edd8-4cd0-9fa2-491eced1680e}",
      "strict_min_version": "42.0"
    }
  }
}