Sure, there are some excellent calculators in the Android Market, but do any of them make you hesitate for a minute when looking at them to figure out whether you are staring at a phone or a smaller version of your favorite Texas Instruments machine? Doug Melton's ports of the popular AlmostReal TI-83, TI-85, and TI-86 emulators to Android are so successful, most of your professors wouldn't even know the difference if they saw one of these on your desk. The buttons, the layout, the graphics, TI-BASIC program support - it's all there. Awesome.

I'm not sure whether Texas Instruments goes after emulators of its calculators, but I would download these ASAP if I were you.

P.S. Unfortunately, the TI-89 version is not available, but we've reached out to Doug to see if he might release one in the future.

Download

TI-83

Get a TI-83 emulator for your phone! The TI-83 graphing calculator is great as a standard calculator, but also great for statistics and trigonometry. Graph and compare functions, and perform data plotting and analysis. Write programs in TI-BASIC.

The app was not found in the store. :-( Go to store Google websearch

TI-85

Get a TI-85 emulator for your phone! The TI-85 graphing calculator is great as a standard calculator, but also great for engineering and computer science. Graph and compare functions, perform bit manipulation and convert between numeric bases. Write programs in TI-BASIC.

The app was not found in the store. :-( Go to store Google websearch

TI-86

Get a TI-86 emulator for your phone! The TI-86 graphing calculator is great as a standard calculator, but also great for engineering and calculus. Graph and compare functions, perform bit manipulation and convert between numeric bases. Solve differential equations, plot vector fields. Write programs in TI-BASIC.

The app was not found in the store. :-( Go to store Google websearch

Update: Also check out the HP 48 emulator, which has been available for quite a while now.

Droid48

Emulator of the HP 48 scientific calculator, using RPN. Port of the X48 project (sources available on github). HP48's "grayscale mode" cannot be emulated.

Visit www.hpcalc.org for a large program collection.

Cool tip: tap the HP's LCD to show/hide a simpler numeric pad!