15C Pro Scientific Calculator 4+

I had been using a different 15c app, but this app-which I already had gotten, I suppose, DOES work with the latest upgrade. I am still getting accustomed to the ‘look.’ It’s a bit shiny-like a brand new HP15C-I can’t remember that far back can you? But I can’t calculate with any other system.
Mostly I have done simple math, but you can’t beat that back arrow key once you are deep into a stack. Speaking of which I have to give a shout out to my brilliant Principles of Finance professor. As we were working in class I said, “Where is the formula?” He said, “You don’t need the formula.” Our agreement had been that I could use my 15c (instead of the calc they suggested) as long as he didn’t have to help me put it into my calculator. All I said was, “I need to see the formula to put in the stack.” The man not only knew the exact page off of the top of his head, but since my 15 C would give ever so slightly different answers than the ‘suggested’ calculator, as he came around to me in the class he would tell me exactly what number I should have. He did all the math in his head while teaching the rest of the class. I couldn’t ask for a better business professor! I learned so much more from him than how to press people’s buttons. Go Cougars!

As well as being affordable, this app seems to properly save the state of the calculator, including programs and registers, when the program is stopped or the IPhone rebooted. The free app and HP’s overpriced official version do not, a disqualifying flaw. Who wants to re-enter their programs whenever their device reboots?

No flashing display after running a program, a silly uncorrected bug in HP’s app. Plus, this one has a well-done portrait mode and an excellent help that includes the full manual. The key clicks sound good and are switchable from within the app. Haptic feedback capability would be nice. Programs seem to run somewhat slower, but that may be eye candy so the “running” display can be displayed for a second or two during program execution. Feels much like the original. Love it.

After the app had stopped to work a while ago due to an iOS update, the developers finally delivered a version that work ms again on the latest release of iOS. This is the 2nd best calculator - the best bring my real HP 15C. If you know how to use the original calculator, you will be able to use this app as well. It behaves just like the real deal.

To the developers: Please make sure that the app keeps on working through any future operating system updates.