I haven't gotten around to changing boot screens yet, but I run Rainmeter on all all my machines, and this is my current desktop on my Windows 10 laptop. The photo is HD, and I have a lot of those. It's a slideshow run by one of the Rainmeter widgets and it refreshes every 4 hours.
I would like to thank the guys at Windows Central for making such a useless app on PC and Windows Phone. Meanwhile it works great on Android, oh by the way you also have to pay for the app on Windows devices...great job guys