In this photorealistic simulation of a spring pendulum a mass is attached to two springs. You can touch the mass and move it out of it's stable position. Or you can tilt your iPhone and watch gravity work. At all times you can alter the damping (k), the flexibility of the spring (D) and the mass of the steel ball (m). Take some time and play around with these parameters to become an expert in harmonic and not so harmonic oscillations. If you have found an interesting one, tap the red graph symbol to record the displacement over the time. Double tap the diagram to save them into you photo library. Have fun learning physics!