225 different 18.5: 9 (Samsung S8) aspect ratio wallpapers. I've collected these over the last few years, don't have sources. Some photos are my own. - mobile wallpapers post - Imgur
Note 9 Wallpapers - Wallpaper Cave
Tall Wallpapers 4K AMOLED 18.5:9 Aspect Ratio - AppRecs
18:9 Wallpapers - Top Free 18:9 Backgrounds - WallpaperAccess