littleBits created a system of magnetically connected circuit building blocks. It didn’t do much to teach you about circuit design and electrical engineering, but was intended to abstract signal as a toy and prototyping tool.

There’s a surprising amount of prior art though. Lectron was a tool from Raytheon in the 60s that encased electronic parts in clear plastic dominoes with magnets to ensure electrical contact when tiled side-by-side. The problem it solved was breadboarding: kids especially could more rapidly cobble together circuits this way, swap out a resistor, change a push button for a potentiometer, etc. The level of abstraction was certainly that of a Radio Shack 30-in-one electronics lab.