Hi all; I'm the author of RpnCalcPro. It doesn't have the same layout as the HP12C (I intended to use it in portrait mode), but it has all the same functions except for programmability. It's $5 at present. More info at
RpnCalc Pro
I've gotten some feedback from people asking that I make they layout exactly like an HP12 in landscape mode, so I'm working on it. It's a little tricky because an android screen is much smaller than a real HP12, so squeezing it all in is rather difficult. I have it working now for the Archos, and with a little tweaking, I can get it to fit on G1 and Droid. Look for the new layout soon.
Since I have a number of interested people here, I'd like to do a quick user survey:
Do you use the programming functionality of the HP12? I haven't seen a need to add it to the calculator app, but I might if there's a demand.
Do you find the HP12's n,i,PV,PMT,FV functions ambiguous? That is, do you have trouble knowing if the key will enter a value, or compute it? (I added a "Find" key to my calculator to remove the ambiguity, but maybe it's not needed.)
Also: the cash-flow calculations (Cf0, Cfi, etc.) Do you ever use these? Do you edit the stored values? Do you change the Ni values?
Other differences between the android app and the real thing: I have 20 memories, whereas I think the real one only has 10. The stack has 16 levels instead of 4. Statistics have their own registers rather than being stored in the main memory registers. I'm going to guess this doesn't cause anybody problems.
In general, I'm interested in whatever feedback you might have.
-ed falk