Out pals at adafruit have just released Circuit Playground, an app for iPhone and iPad that combines a bunch of handy electronics references and calculators in one attractive interface. It’s $2.99 from the AppStore. An Android version is reportedly in the works, but I understand the adafruit folks are not in too much of a hurry to horn in on the good work that Demetrio Iero is already doing with ElectroDroid.