“When you tapped the zoom button on our iPad demo, the keyboard you were looking at (say, mine) transitioned to the other one (his), much like clicking to go to the next slide in presentation software like Keynote or PowerPoint. The image of one keyboard disappeared to nothingness to reveal the other underneath. Bas added scaling to his animation—the keys of the departing keyboard changed size to match the one coming into view. He also tuned the timing of the animation, so it started slowly and sped up as it went, making you feel you had definitively landed once the animation finished. These effects were subtle, given that his animation was a mere fraction of a second, but Bas had a way of making these details count. When you looked at this zoom key animation, it appeared as if the keyboards were undergoing a complex morph. They weren’t. From an engineering perspective, this was significant, since the simplicity of the design meant I could write the code for his animation in just a couple hours. The magic was in the overall effect. The animation didn’t look like clicking from one slide to another in a presentation deck. When you tapped on the zoom button, it made you feel like one keyboard was becoming the other. The effect registered viscerally. It was exactly the kind of self-explanatory touch that made Apple software easy to use.”