LightUp is an interesting project that allows to build small electronic projects with ease and then use an interactive augmented-reality application to understand and visualise how the design works. Oh, how I wish we had this when we were kids!
They use components that are attached on a block with magnetic ends that are easy to combine and create a real electronic circuit. Then you can use their app to see how it works or to debug in case of errors.
Check out their page on kickstarter.