Examine source code of Device-Detect

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Device detection (phone, tablet, desktop, mobile, grade, os, versions)",
  "icons": {
    "16": "assets/icon_16.png",
    "128": "assets/icon_128.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "assets/icon_16.png",
      "38": "assets/icon_128.png"
    }
  },
  "applications": {
    "gecko": {
      "id": "@devicedetection",
      "strict_min_version": "45.0"
    }
  },
  "manifest_version": 2,
  "minimum_chrome_version": "42",
  "name": "Device Detect",
  "permissions": [
    "tabs"
  ],
  "short_name": "Device Detect for your mobile browser",
  "version": "1.6.1resigned1"
}