Tim Mossholder is the photographer and from his courtesy the apple fruit image can be downloaded under CC0 license. The apple photo is optimized here for fit as desktop background and homescreen phone. Also if you need it in other projects just download and resize it to fit your needs.
Widescreen Desktop / Macbook (Retina): 2880x1800 (fits on: 2560x1600, 1920x1200, 1440x900)
High Definition HD 1080p: 1920x1080 (fits on: 1600x900, 1366x768, 1280x720)
Samsung Galaxy Tab & iPad: 2048x2048 (compatible with many tablets)
HTC, Samsung Galaxy & iPhone: 1080x1920 (compatible with many phones)