There are now numerous math programs for the Android platform, including calculators, graphing programs, programming languages and a collection of Matlab clones.

Calculators are often developments for the Android platform. But some are emulators of well known hardware. Here is one for the TI86 called Andi Graph. You need a TI86 ROM for it. You will be able to get such a ROM.

Many students grew up with this calculator. It is a great emulation. Here is another one for the HP48 called Droid48. It is particularly interesting since the HP48 was one of the first calculators with algebraic capabilities. It features inverse Polish notation, which is like Greek for most users.

I once possessed one of those. If you ever find it, return it to me. I still have a manual for it (in German).

Arity takes an original approach. It is an open source software, and I have the sources from Sourceforge. I always wanted to improve its cumbersome interface, but probably never will manage to work on it.

It is actually not a bad calculator, but I find the keyboard too hard to use. HandyCalc does a better job with the keyboard, but I find its interface very confusing. It is a mighty program, however, and might be worth the effort to learn it.

There are some notebook style programs. One of them is MathScript, which I do not like too much. You enter an equation on a separate page, which is then inserted into a notebook and executed. The editor is OK, and also the notebook, but I find this style too complicated. And it has bugs with keys in the editor.

My favorite is currently MathStudio. The app is more expensive than a usual Android app. But I don’t regret to have bought it. It’s interface is clear and easy to use. The plots are great with OpenGL. The math is bases on Yacas probably, and works well.

Here is 3D plot. It can be turned fast and easily.

The program has a great Tablet interface, which is still rare.

It also features Yacas bugs like

\(\lim_{n \to \infty} n \left((1+1/n)^n-e\right) = \infty\)

But really

Euler gets this correctly.

Another option is a web based program like Wolfram Alpha. You can use their service on the web site, but there is also an Android App.

This is clearly the most feature rich choice, but also the slowest. And you need an internet connection.