Florens Verschelde, on the design of calculator apps:

At the risk of beating a dead horse, I’ll argue that Soulver’s design is “skeumorphic” as well. It reproduces the experience of writing calculations on paper with a pencil, writing down a result, referencing that result later on, etc. (...)
Soulver’s design is superior not because it is less of an imitation, but because Zac [Cohan]’s choice of what to imitate was better.