Hi, adding custom widget background is a bit tricky. There is not direct input, but can be added this way :
1. In game : when you edit widget, there is ‘+’ button near image. This will add custom foreground image. But you will be able to pick this image from backgrounds too. I will add user input in one of next versions.
2. You can add this manually. Find folder Magicbox on disk. There is another folder Games with file games.xml inside. Check your game ID and than in folder Data find folder with this id. There should be folder Images (if not create it). Copy your images there. !Important! Files must be png and name must match this rule : Must start with “user_”, example : “user_imagename.png”. This way omits image size restriction (192x192px), but it is strongly recommended to not use big images.