Great news - Vicinno's HP 15C Scientific Calculator iPhone app is FREE now


Hi HP fans,

Just joined here and glad to see so many HP calculator fans. Hope you like my first post here about our free promotion:

Vicinno just made its popular 15E Scientific Calculator iPhone app, a truly emulator of HP 15C Scientific Calculator, FREE for a limited time. Grab it before the sale ends in a few days.

Download it FREE from app store

Also please tell us how you like it, welcome any comments.

John Y.
Product Manager of Vicinno

Edited: 5 June 2013, 1:47 p.m.


69.5 CHS x! takes about 13.2 seconds, exactly what it takes on my original HP-15C, and returns exactly the same answer: -1.527756643e-97. Very nice! Perhaps a reason to finally get myself an iPhone (tested it on my wife's).
Thank you for making it available for free!



Glad to hear you like it, which will motivate us to work harder to improve it. Feel free to contact us at if any questions later.



John, Thank you for this gift. I got the Vicinno 12E in 2011, so it is nice to get the 15E, which to me is a brand new machine as I never got the original. It I could make one suggestion, it would be to add a stack view as some of the other RPN emulators have done. A very nice calculator! Thanks again!


I will forward your request to our dev team. they will do the research and give a response soon.

btw, can you give us more info such as why you want that feature. I am not quite sure why people care about the stack.

Your feedback will be highly appreciated.



Hi John,

A Stack View is incredibly useful. In manual as well as programming situations, it is easy to forget what values are in the Y, Z & T registers, or in what order.

In debugging a program, it is most helpful to see where certain values are in the stack so we can program most efficiently. Also for functions and that return multiple values to the stack, a stack view lets you instantly see the results. A good example is the Rectangular to Polar conversion and vice versa.

if you look at some of the other 11C, 12C, and other Voyager Calculator emulators out there you will see that some have included the stack view.



I would like to see a stack display too.

I use the 11C iphone app from RLM tools and I always have the stack display on. At first I used it as an easy way to make sure I had entered the right thing. Because the touch interface is so error prone with the small buttons (and my fat fingers), it was an easy way to spot errors.

After a while, however, I got really used to the handy display of the stack and I miss it on my real calculators.

I've tried your 15c app and though I prefer the 15c to the 11c as a calculator, from a human factors standpoint the 11c app I use really nails it and for some reason is just a little more comfortable to use. I think that the calculator display uses a much larger font, the buttons are just a tad larger, the font on the buttons is a little larger and bolder and the contrast of the dark background and the fonts isn't as harsh.


John, at the risk of asking too much...
It would be really useful to include a view of the imaginary part of complex numbers. If you look at some of the other emulators that do complex numbers, some show both the real & imaginary parts. That really helps!

Thanks for listening!


Thanks for all the feedbacks. We definitely will consider all of them and try to add them in. I will talk to our dev team soon.



Why so slow? RPN-45 SD, for example, returns the same answer instantaneously, so there's no technical reason for the low speed.


Perhaps this is actual calculator speed, as in the Nonpareil simulator, for instance. An option for maximum speed should be desirable.


Hi, John.

Any plans on doing the same for us, poor Android folks? :-)

Thanks in advance



Welcome to the Forum. Thank you for the 15C app. If you need beta testers this Forum will find a bug in a cave, in a hole, under a rock 4,200 ft. below the surface of Mars.

Any plans for a 16C version?


Yes, we are planing 16c now and will release it soon. Thanks for your feedback.



We have Android 15C calculator app, but unfortunately it is 9.99$, not free now. Sorry about it. I will forward your request to Android team. hope they can consider it.



That will be great. Thanks.



For android, search for go15c go16c go11c and for go12c.

The last is free, but for all you need to have your own rom dump.



Thanks. Any plans for a 16C?


Seems the 10C is a collectors item, also it's emulation.



Egan, see my post, and John's reply, above... #10.



Edited: 7 June 2013, 11:11 p.m.


Does it pass the {ON + *} test?


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