After having seen the IOS and Android apps I was dissapointed to find there was no NewRelic client for windows phones/windows. So I made one! it is still a bit rough around the edges and requires you having access to an API key on your account.
Available for Windows 10 and Windows Phone 10 (and hopefully xbox one if Microsoft ever simplify the process for apps in the store) - Search for NuRelic.
I will keep an eye on this thread for any feedback.