Version 1.1.10 (iPhone/iPod Touch)

• Fixed a sampling problem that resulted in vertical portions of graphs not being drawn.
• Improved the root/intersection finding algorithm.
• Added a proportional zoom option.
• Fixed a problem related to the “ans” key.
• Calculator history is now saved when you quit the app on iOS4.
• Fixed several minor bugs that people found since the last update. I would like to thank everyone that e-mailed me.

Version 1.0.2 (iPad)

• Everything you see listed for version 1.1.10 of the iPhone/iPod app.
• Added video output support, which was requested by several teachers. You can now connect the iPad to an external monitor in order to display the graph view.
• Added a left-handed keyboard layout option that repositions the number pad.

• Fixed a bug responsible for crashing the application on iOS 4.
• Multitasking support that allows you to jump back to where you left off (only using iOS 4).
• Updated the graph logic, buttons and icons to look great on the new retina display.
• Changed the keyboard’s click sound to match Apple’s default keyboard.
• Fixed a problem with the nPr() function.
• Corrected an issue with gamma() and lgamma().

I had a good idea what my graphs would look like on the new retina display, but seeing it person was still shocking. I can not see the individual pixels that make up curves, which looks great. I would like to see a display with a similar pixel density for the iPad.

Quite a few people have asked me whether or not an iPad optimized version is coming. The answer is yes, and I started working on it the day I received my iPad. I will try to get version 1.0 finished within a few weeks from today. The first version will match the feature set of the iPhone version, but as time goes on it will be able to display much more information thanks to the bigger screen.

A friend of mine told me he saw my calculator pre-installed on an iPad demo unit at a Best Buy. I just had to go see it for myself, and I found my application pre-installed at the local Apple store as well.

A picture of me at the Apple Store

The iPhone version works well enough on the iPad that Apple decided it was a good demo for iPhone backwards compatibility. The buttons and fonts are huge, and it’s a bit pixelated, but it works well. If you wish to take a look before you buy my app, visit an Apple store (or Best Buy) and you can play with it on an iPad demo unit.

• Added the ability to find local minimums/maximums while tracing the graphs.
• Added the following trigonometric functions: asinh(), acosh(), atanh(), cot(), csc(), sec(). The inverse hyperbolic functions were requested by many people.
• Added the following new functions: gamma(), lgamma(), nCr(), nPr(), min(), max()
• Fixed the sin(asin(x)) graphing problem discovered by Sven Hörbeck.
• The function selection page now has a fixed cancel button up top.
• Added a comma button to the keyboard in order to support functions with multiple input parameters.

I had a stable job that paid a competitive salary, but what I really enjoyed working on was my side projects and this calculator. To follow my dreams, I decided to quit my job and dedicate all of my time to mobile application development. This means I will dedicate my full attention to this graphing calculator starting next Monday. Expect to see many new features and more frequent updates over the next few months.

If you enjoy using this calculator, and you would like to help me keep the price at $0.99, I would appreciate if you took a minute to rate the application on iTunes.

• Redesigned the calculator screen so that it’s easier to use.
• Enlarged the buttons.
• Added the ability to fix or edit previous calculations.
• Calculator history is saved even if you restart the application.
• Redesigned the equation editor for improved usability.
• Added an option to zoom only the x or only the y axis.
• Due to popular demand, there is now a square root button on the main keyboard.

• Added polar and parametric graphing support
• Added a random integer function
• Improved graphing speed, which was needed for the more complex polar/parametric graphs
• A few minor bug fixes and improvements

I also spent some time changing the look and feel of this website. The header image actually has two screen shots showing off the polar and parametric graphing support. The smiley face was created using 4 parametric equations, and the polar graph is showing the graph for: r(θ) = sin(10 * θ / 7).

In addition to adding polar/parametric graphing support, I fixed a few minor problems and improved the graphing speed. I have some really good ideas on how to improve the usability of the calculator screen. Many of you sent me great suggestions, and I would like to thank all of you. Version 1.1.6, which I’m going start working on shortly, will have a completely redesigned calculator screen with a large number of new features. I’ll post more details once I get closer to releasing it.