I love the Android wallpaper switcher Muzei but the photo selection for Google Photos required you to select photos individually.
Luckily Muzei makes it easy to build your own wallpaper sources so I created this which fetches meta (ID and created time) for all your Google Photos and serves up a random one which hasn't been seen yet each time Muzei asks for a new wallpaper. Once you've exhausted all of your photos it starts over.
Leaned heavily on code from 500px example and Google sample code