4K HD Wallpaper: Sailing Ships
From Peter's portfolio is this photography that can be downloaded free under CC0 license and use in social media, content marketing, blogs, desktop backgrounds, homescreen phones...
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 almost all tablets)
HTC, Samsung Galaxy & iPhone: 1080x1920 (compatible with many smartphones)