This is a great site with free downloadable software for children with learning difficulties. It would also be appropriate for very young children too.
Switch videos are animations or slideshows set to music, which can be controlled by a range of common assistive access devices. They are designed to help children understand and generalise cause and effect (the action / reaction bond), one of the foundation stones for early learning. All of the videos can be played online or downloaded for use on a PC or Macintosh computer.