TOMECK  Probably you have seen the following offer from their website already but just to make sure:

"The full version of PCalc for the iPhone and iPod touch includes a discount coupon code to save $9 on the price of PCalc for Mac OS X. The Mac version is normally $19, but with the code you can get it for a mere $10. So, if you were thinking of buying both, it's like getting the iPhone one for just 99c!"

I believe that is a great offer, at least if you have a need for both versions...   
(Version 3.5.1)

TOMJWRIGHT  Correcting my previous post - It was actually in the early 1990s that I started using pCalc. I guess I'm so used to having it on my computer that I thought I had it earlier. Anyway, it's a great calculator that only gets better over time.  
(Version 3.5)

FRIEDDYLAN  You know you're right, but I think this is a different product idea you have. I suggested textbook output and input as well to better facilitate Quadratics and Matrixes. Its a tall order for the price rand but would definitely get my money. I need a good laptop based graphing calc to match my TI nSpire with CAS and this guy's code seems readily able to pull it off.

We would sit back and watch what he does. I'll buy the first graphing version that allows me to view tables based on my graphs. Of course allowing me to drag the graph around and capture the values in a table would be completely awesome. That's like superhero coding.. complete with codpiece!

:)  
(Version 3.5.1)