Step forward.... Pocket Clanger Theremin!!!!
Yes, you play it with a stylus or your finger, not an antenna. But apart from that it has all the features of a theremin, and a nice picture of Tiny Clanger on the playing area, Controls for delay, feedback, frequency range, etc., and sounds REALLY weird. Fun for all the family! And freeware too!
I don't seem to have a clanger icon, so Smurfette will have to do.