Overall most functions work and some don’t work.
I have tried to contact the technical support person for this application about several issues and have not heard back from him. The currency exchange converter is not working properly for a number of currencies such as Swiss francs (CHF) to US dollars. Negative numbers are miss handled and miss calculated going from Prog mode to Math mode. This application needs to reverse engineer how to handle negative numbers from the HP 16C calculator. In statistics mode when a logarithmic plot is made with a correlation of better than 0.999, the x axis approximation is severely miscalculated when the X,R button is pressed. Try this for yourself. The y axis approximation works nicely for the logarithmic curve plot. In the short time frame that I have been using this application I have found these issues. Most other features and functions are working perfectly well. There is probably more features that are not working which may make for another review by someone else. Overall this is a good application to experiment with and is worth the six dollars.
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Love this Calculator
Had to have an RPN calculator, and this one has zero downsides. It like every HP in one. The developer is attentive to keeping it up-to-date with ios changes.
Still the best RPN Calculator app out there!
I grew up with an HP 35 and moved to the 11c. This app is superior to HP. So much more capability and usable functions. I have been using this RPN calculator since it came out many years ago and I love it! Great for engineering calculations, conversions and financial. This is a great product for a die hard engineer that grew up on RPN! Thanks for keeping it going!
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Best RPN Calc
I grew up using the HP42s, which I loved. I have the phone app for the HP42 also but I use this app as my go to app. Easy to use with all of what I need within a few strokes.
Better than HP!
Didn’t think I’d ever say this, but this calculator is better than HP’s. Of course, it doesn’t have all the cool stuff built into a 15, for example, but for what it does it’s very thoughtfully designed and works conveniently well. I also like all the trivia and background sprinkled throughout the documentation, FAQ, etc. Not only is this a very well-designed and useful calculator, but it also educates you on some of the history and science behind implementing floating point math in a binary machine. I’m a very happy customer.
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Awesome
Best smartphone calculator out there!
Love the app
Really nice app. Does a very good implementation of RPN, and has numerous useful functions. I use it every day.
The best!!
Hands down, the best calculator anywhere. If you’ve ever used an RPN calculator this is the one you need. If you haven’t used an RPN calculator, you should learn so you can use this one.
Absolutely the best.
Absolutely the best.
Great RPN calculator!
Beautifully implemented, with all the usual functions and many unexpected bonuses (e.g., currency conversions, 12c-like financial functions, stat plots with regression lines, etc.)
Go-To Calculator
A super all-in-one tool. I’ve used it every day for years. The conversion tool is especially helpful.
Best and most comprehensive financial calculator on the market
Highly recommend
Not for iPad
The description says it is optimized for iPad but it’s not. The display is fixed for portrait, does not fill the screen and looks fuzzy. I uninstalled and will try to get a refund.
Glad to see the update!
I have been using this RPN calculator for a number of years and I love it! Great for engineering calculations, conversions and financial. This is a great product for a die hard engineer that grew up on RPN! Thanks for keeping it going!
Excellent Calculator
Once you’ve learned RPN, you can never go back. This calculator is very easy to use and super reliable. If you know RPN, you’ll be very happy. If you want to learn, this calculator is a great reason to make the jump.
Great calculator !
I’ve been using this app for years, ever since I lost my HP41. I only got it as a temp, but it quickly became full time. If you like using RON, you can’t beat it. Plus, it’s got a lot of features my old HP didn’t. I find the conversions very helpful (cu yds - cu in, km - mi, etc)
Awesome RPN calc
I’ve been using this app for quite a while and love it!! Thanks!
Love this app
Really nice if you’re used to RPN calculators. I use it daily.
AllRPNCalc
For my needs, this is the best rpn app I’ve used.
Super duper awesome in all the right ways
Comprehensive features, intuitive settings, and a natural user interface. Well thought out and developed calculator. Thank you!
Outstanding RPN calculator...
If you like HP calculators, this app should serve you well.
I have been using this calculator for years, and it remains one of my all time favorites. It takes a successful HP calc and adds several useful features: unit conversions, currency exchange rates. I also value its ability to perform scientific and financial calculations.
I have tried and used more than 20 calculator apps. Some do offer features not in this one. However, it is in my top two calculator apps.
So glad the developer has updated this app to be compatible with current iOS versions. Hope other legacy app developers will do the same. The fear of losing this one kept me from being willing to update to the latest iOS.
UPDATE: Been using this great app for years, and it never lets me down! Kudos to the developers who have kept this app working throughout all the many iOS changes by Apple.
I have been using this calculator for years, and it remains one of my all time favorites. It takes a successful HP calc and adds several useful features: unit conversions, currency exchange rates. I also value its ability to perform scientific and financial calculations.
I have tried and used more than 20 calculator apps. Some do offer features not in this one. However, it is in my top two calculator apps.
So glad the developer has updated this app to be compatible with current iOS versions. Hope other legacy app developers will do the same. The fear of losing this one kept me from being willing to update to the latest iOS.
UPDATE: Been using this great app for years, and it never lets me down! Kudos to the developers who have kept this app working throughout all the many iOS changes by Apple.
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