This is an interesting utility - and I'd not heard of it until yesterday! Field Medic is an official Microsoft utility, for Windows Phone 8.1 and Windows 10 Mobile, designed for when Microsoft support helps you remotely. The idea is that every last minute detail about your hardware and software is gathered, along with real time reporting on what the OS is doing. And it's free, of course. Of zero interest to casual users unless they have a problem, but very interesting for uber-geeks and AAWP readers!

From the minimalist Store description:

Field Medic is the premier diagnostic application for Windows Phone. This tool allows easy collection of device information and ETW logs right from your device.

Here's Field Medic in action:

Logging data from my phone in real time - you get to name the logging session and then it's just a folder of files on your storage that a remote support guy can access if needed.

Some of the excruciatingly detailed information screens (slightly redacted here) - you won't believe how much there is here - dozens of pages of under the hood data!

You can grab this in the Store here. Worth installing for interest's sake?

PS. Of course, some of this is now built into the Windows 10 Feedback Hub application, but the original (and more detailed) app is still worth installing.