HD Wallpaper: Hourglass
If you look for a photo related to a hourglass check this one which can be saved under CC0 license from courtesy of Nicole. The image is optimized here for fit in desktop backgrounds adn homescreen phones.
Widescreen Desktop / Macbook (Retina): 2880x1800 (fits on: 2560x1600, 1920x1200, 1440x900)
Samsung Galaxy Tab & iPad: 2048x2048 (compatible with many tablets)
HTC, Samsung Galaxy & iPhone: 1080x1920 (compatible with many phones)