Very well done; can be tightened up

Excellent port of my trusty 12C. I very much like your add of the register displays under the main display panel. Like some others, I am impressed how much extra speed you have been able to wring out of the old routines using the iPhones much newer processor. I hereby offer a few suggestions for your update list:

1) Echoing others, key clicks are critical.
2) The yellow f and blue g key labels could be slightly dimmer in normal display mode, especially since you highlight them on pressing the function keys (a nice touch). This would be less distracting.
3) Similarly, the white key labels could be slightly dimmer, too (and/or the black background less dark). The contrast now between all labels and the keyboard background is so high that it will be tiring to look at for extended number crunching.
4) I know you are working from a photo of an actual 12C, but all the key labels and f and g labels could be crisper. Tighten them up with a pixel editor. No reason to be slavish to the past.
5) I would prefer the display panel numbers (results) to be slightly smaller, in favor of slightly larger register contents displays, but this is not a biggie.
6) I would find the original bond math functions useful. I would not miss the program functions at all. Some will disagree with me.
7) Would be nice to have the [f] prefix function, to temporarily display the panel number in floating precision, but no biggie, either.

Well done, and heading toward a five star review with your updates. Am curious to see what new, soft functionality you decide to build in. Your calculator could end up putting my original out to pasture for good.

Old banker about Calculator12 RPN