Basic environment flags for Cordova apps with installed Device plugin. Note that the Device plugin is not available before the Cordova "deviceready" event has been fired.

cordova_environment.js

env = (function(){
  var flags = {}, i, osVersion = device.version + '', androidVersion,
    el = document.createElement('div'), root = document.documentElement

  function flag(names) {
    names = names.split(' ')
    for (i = 0; i < names.length; i++) flags[names[i]] = true
  }

  function classnames() {
    var names = [], name
    for(name in flags) if (flags.hasOwnProperty(name)) names.push(name)
    root.className += (root.className ? ' ' : '') + names.join(' ')
  }

  if (device.platform) flag(device.platform.replace(/-/g, '').toLowerCase())
  if (flags.amazonfireos) flag('android')

  if (flags.ios) {
    flag('ios' + osVersion.match(/\d+/))

    if ('i386 x86_64'.indexOf(device.model) > -1) {
      flag('simulator')
    } else if (device.model.match(/^(iPad|iPod|iPhone)/)) {
      flag(RegExp.$1.toLowerCase())
    }
  }

  if (flags.android) {
    androidVersion = osVersion.match(/^\d+\.\d+/) + ''
    if (androidVersion === '2.2') flag('froyo')
    if (androidVersion === '2.3') flag('gingerbread')
    if (androidVersion === '3.2') flag('honeycomb')
    if (androidVersion === '4.0') flag('icecreamsandwich')
    if ('4.1 4.2 4.3'.indexOf(androidVersion) > -1) flag('jellybean')
    if (androidVersion === '4.4') flag('kitkat')
    if (androidVersion === '5.0') flag('lollipop')

    // Android Virtual Device (emulator)
    if ('sdk google_sdk'.indexOf(device.model) > -1) flag('avd')
  }

  el.setAttribute('ontouchstart', 'return;')
  if (typeof el.ontouchstart === 'function') flag('touch')
  if (navigator.msPointerEnabled && navigator.msMaxTouchPoints > 1) flag('touch')

  if (navigator.devicePixelRatio && navigator.devicePixelRatio >= 2) flag('retina')
  if (screen.width > 1280) flag('hd')
  if (screen.width < 768) flag('narrow')

  classnames()
  return flags
})()