ND1 app for iPhone and iPad

This is certainly one of the best current project to develop the next generation all purpose scientific RPN calculator (HP should have done it but they have now unfortunately retired from this market). ND0 and ND1 go beyond the best calculators ever designed by HP (in the 28, 48, 50G series). It is easier to use, has great programming features, is faster. The author seems very responsive. If you are a scientist or an engineer this is definitely an excellent choice. The only missing feature for me is the CAS, but the interface with Wolfram solves partly this issue. A built in 50G CAS and this would become the dream machine... The ND1 version is really cheap given all the features (unlimited stack, ...) A new HP50G is +100€...

This RPN calculator is truly amazing! ... both in its current capabilities and in its potential for future development. For anyone whole truly appreciates a powerful fully programmable scientific calculator, I have this simple word of advice: GET IT NOW! You will not be able to put it down ... but also a word of warning: be careful, because once you discover what this calculator can do you may end up "wasting" a lot of time because it can be very addicting. Definitely 5 stars.

I have only written two reviews for an iPhone app: the ND1 1.6 and the prior 1.5 release. This is a suburb app that should be on every scientific-minded/computer-literate users iPhone. The recent update builds on the already amazing ND1 1.5. The big addition to this version is that ND1 is now a Calculator Generator, allowing one to make their own customized Calculators. How cool is that! I have always enjoyed the HP 42s, so I used ND1 to design and build a customized HP 42s+ for myself. Even out of the box, without customization, the latest release of ND1 (1.6) is arguably the best RPN calculator app available on any mobile platform. (Trust me, I know. I have owned HP/RPN calculators since my HP-45 decorated my belt in High School. Dont tell my kids friends. . .) The ND1 provides a significant subset of the functionality of the HP 48/50 class calculators. But rather than being just another emulator, fixated on replicating the "classics" and repeating the past, the ND1 pushes forward. It is as much of a calculator development platform as a calculator. It is extremely configurable. Not only can one reconfigure the keyboard and its keys, but one can affix ones own code to any key. Moreover, this can be done in native RPL+, in JavaScript or in combination. As a result, the ND1 is able to work with a wide variety of classes, including the traditional numeric classes, but also BigInts, Rationals, Complex, Colors and Images. (Classes, as well as other customizations, can easily be created by the user and shared with the broader ND1 community.) Here-to-fore, my favorite RPN iPhone app has been the HP 42s (which I rate 4 *s). Though its an amazing replica of the original, the project is focused on recreating the 42s, as opposed to pushing forward. Though superbly engineered, it was done at a time when dynamic reconfigurability of the keyboard/functionality was limited. In contrast, the ND1 is easily reconfigured. Currently, I am taking a Chemistry course, so I wanted a 42s type calculator that has physical constants built-in. I was easily able to reconfigure the ND1 to do so. Moreover, for my day job, I wanted to include a core-set of financial functions, which I was also able to easily add. As impressed as I am with ND1 in its current incarnation, I believe the best is yet to come. I believe that the developers of ND1 will continue to focus on configurability and expandability. Lest you feel intimidated by all of the power of the ND1, dont be. As I mentioned, it is ready to go right out of the box, but its nice to know if one wants to make "tweaks" that these can be easily accomplished.

Truly excellent. I owned a 48SX and Im upgrading from a 48 emulator. This is a better and absolutely worth the money. To me, killer features are fullscreen stack, variables in matrixes, and the folders. I like how cute, easy-to-use, and well-thought-out it all is. The attention to detail is apparent. I dont program, but Javascript programmability seems to be the other killer feature. Im waiting to see what people will come up with. The demos are very impressive. Two things I would love (and make this deserve 6 stars) are: an equation library and an equation writer. I know I could import equation data myself, but Im too lazy to type this all up. Highly recommended. Check out the website. Theres much more documentation than I ever saw for an app!

I have an HP 28s again. The HP 28s was the only RPN calculator I enjoyed using. I bought one in 1988 and it saw me through high school and an engineering degree. Its great to have one back in my hand. I considered rating the app 4 stars because of some UI nags, but given the apps price, its faithfulness to the original calculator, and its expandability, I have to give it 5 stars.

Best RPN calc, IMHO. Feature set is vastly superior to what else is out there. Being able to upload/download data is wonderful. Starts up quickly and continues where you left off. @jdubiner: has key clicks now.

Difficult to rate! Unfortunately the app developer has gone AWOL - forum links does not work. Hope it is only a temporary situation - but apparently long time since updates.

I have read all the tutorials for this and entered the equation for a circle. It said there was no such variable "y".

This app is a mess. Keys are in the wrong place. Even Apples calculator is better...