Sometimes you have a pixel-art image that you want to use as wallpaper, but the aspect ratio is different, or it is too small, or doesn't scale cleanly to your resolution. This small online tool lets you do so much easier - you can insert an image, upscale it to your chosen resolution, and even align it for best results. Scaling is pixel-perfect, and you can scale down the image if the original is already scaled up.
Have fun!