I've created a game using my Window Gamesalad but some of the JPG images not visible
when I run it on my iPad.
Try manually turning the images to PNG instead of JPG. Gamesalad is supposed to do that on import I believe but maybe there is an issue with that.
http://jamie-cross.net/posts/ ✮ Udemy: Introduction to Mobile Games Development ✮ Learn Mobile Game Development in One Day Using Gamesalad