title: Finding the user agent of native Youtube app for Android and/or iOS
body: <p>I'm currently working on a project to determine patterns in user agent strings that we would consider valid for reporting purposes. Essentially to only report impressions from valid devices. We are starting with what we thought was a pretty exhaustive list but it seems we are missing a big player that is still being filtered. I suspect the pattern we are missing is the user agent pattern that identifies the Android/iOS native Youtube App as it should be different from the in browser youtube video but I am not sure how to check this string. </p>
  
  <p>What is the best way to check the User Agent string of the Native Youtube App for a smartphone/tablet?  </p>