Open in AppCenter
You can view and install this app from AppCenter on elementary OS, or you can preview the listing here.
Turn your oddly sized wallpapers into a piece of beauty. Simply right click on your picture's file, and select "Wallpaperize" from the drop down menu, or open the app and drag-and-drop the images you wish to wallpaperize.
Get Wallpaperize and more on elementary AppCenter, the open, pay-what-you-want app store for indie developers. Every app is open source and has been reviewed and curated by elementary to ensure a native, privacy-respecting, and secure experience.