It's been awhile since we had a theme related post....
Those on Facebook might have seen that I've found an awesome wallpaper app for Android called 500 Firepaper by Chainfire. It links in with 500px and gives you loads of control over the images you see, I favour grayscale on every image so the colours don't blend /obscure icons. Triple tap an open space on your home screen and it'll open 500px (if you've got it installed) with the current image on your homescreen.
Android 4.4.2 Cyanogen 11.0 nightly, default theme with 500 Firepaper changing the wallpaper every hour.
One I noticed the other day with an app icon stabbing a swan in the neck by pure coincidence !

Current desktop images, which rotate around 20 galaxy images
