So, what physics or physics-related apps do you have installed on your smartphones or tablets? Angry Birds does not count! :)
I think there's a tendency to try all those "physics equations" or calculator and stuff, but in my case, I don't find that to be that useful. So all in all, I only have two apps that I would consider to be related. One is more of a "useful" type that I can look up whenever I need to, while the other is more of an "amusement" type.
First of all, I have an Android phone. I would like to have an iPhone, but that's another story entirely. But so far, my Samsung Galaxy S II is working just fine, and it is slowly weening me off from wanting an iPhone. So all of my apps are obviously those available on the Android platform.
The apps that I consider to be useful is a periodic table app called Periodic Droid. I need this because, as someone who deals with materials issue often as part of my job, it is nice to be able to look up properties of elements on the spot, especially in a meeting. I tend to not carry my laptop with me all the time, so having access to a periodic table and search some of the basic properties is usually useful. The Periodic Droid is a free app, which means it comes with advertisement, but you can send in a donation and it will give you a code to change it to a no-ad app.
The apps gives a list of standard info for each element, such as: symbol, atomic number element category (metals, semi-metals, etc.), atomic weight, the phase state at 0 C, boiling point, melting point, electronegativity, crystal structure, period, group, electron affinity (in kJ/mol, but it would have been nice to have it directly in eV), valence number, first ionization potential (in kJ and eV, now that's more like it), atomic radius, covalent radius, ionic radius, sheer modulus, density, thermal conductivity, specific heat, heat of fusion, heat of vaporization, heat atomization (?), atomic volume, year discovered, abundance in sea water (?), abundance in Earth's crust, color, electron configuration, oxidation states, source, toxic or not, carcinogen or not, use (?), number of neutrons, electrons per shell, half-life, lifetime, name of discover/s, name of "first isolator", and monoistopic mass. Phew!!
I certainly don't need all of that, but knowing the electron configuration, crystal structure, electron affinity, first ionization, and conductivity are all useful at one time or another. So these are nice to have at my fingertips, or at least, close by.
The other app that I have is more of an amusement. It is Google Sky, and it is free. Google Sky lets you use your device to look at the known stars and constellations. You hold it up in any direction, and the screen will display all the known stars and constellations that are directly behind it in the sky! It is a very cool app! It will even show if one of our solar system planets is in that view. I've used it to identify a bright dot in the sky that I observed with my naked eye, and it happened to be Saturn. And guess what? I don't think there's an equivalent app for iOS. There certainly isn't a Google Sky app for that platform, since someone did try to look for it.
I've browsed the Android Market looking at other physics/math-related apps, and so far nothing else has caught my eye. So, do you have such an app that you would like to recommend?