This tool is a c64 pixel art generator. Upload a PNG or JPG file and convert it into a retro pixel image. Unfortunately, there is no possibility to make further edits. But your pictures look like they came from a C64.
Use the app: http://c64.superdefault.com/
This app is created by: http://roboteralarm.de/
Upload your own file. Save image as .png. Browser-based software – compatible with Windows, Mac and Linux.