Because Contacts feature still need about 2 weeks to finish it, so I public a simple feature at first.
This minor feature is change wallpaper for your web desktop. You can customize your web desktop wallpapepr in Wallpaper module now. But if you are using web desktop with 'Bridge mode", please don't set too big size (>150K) picture for it, otherwise, it will take much longer time to load it.
If you want to restore the default wallpaper, you can delete the /sdcard/AndroidDesktop/WallPaper/desktop.jpg.