17BII-Pro

I just found this marvelous emulation if my beloved HP17BII+ and it's better -- much better-- than the real one! For those who are unfamiliar, the greatest feature of The HP17 Is the ability to write equations and have the calculator solve for any single missing variable. You can store tons of equations and they are much easier to type on the iPhone keyboard. I use it for many specialty functions in my manufacturing business including pricing of complicated custom made items. The HP17 is far superior to the HP12C (though it doesn't have the nifty key layout) and this version is far superior to the real thing. I use it several times an hour all day every day. Thank You for this!

This app has a number of great standard functions (Time Value of Money, etc) but the Solver emulation is what sold me, and what I used extensively back when I had the HP hardware. Simply create your own equation with your variables, enter your variables and values and it will solve for the one value that is missing! And you can save as many of your own formulas as you like. I used it for figuring weights or lengths on roll goods but you can adapt it your own needs/profession. One of the most user-friendly calc apps imo.

The app has not been updated in a few years so I was hesitant to drop $5 on it, but I did and I am glad I did. This app runs perfectly on an iPhone 7+. I will add that it is not adapted to the 4.7" and 5.5" screen sizes. That isn't a huge deal but for those who care, I give you that information. The app starts up quickly, so the review from 2014 about slow start times is not an issue on newer equipment.