I am making programs that solve and show work for math problems. I would like to add a GUI, and I think wxPython will be best. If I use wxPython for the GUI, will the end user need wxPython on their computer in order to use the program with the GUI? If not, what would should I use? 
These apps will be used on mostly Windows, but I would also like them to work on Macs and Linux. I'm not for sure if any Python GUI elements will work on Android through SL4A, but if you know any, that would be appreciated.
Also, I know Tkinter is bundled with Python, but is it a dying technique, as I have read?
Thanks!
Tkinter comes with Python, so it can be handier in some respects just because of that. On the other hand, wxPython uses the native widgets of the OS (which has it's own set of pros and cons). I personally prefer wxPython. But no, Tkinter is not dead to my knowledge.
You can use py2exe to bundle up your app on Windows or you could use cx_freeze or bb_freeze. There's also PyInstaller, which I think can create some kind of Linux bundle, but the docs are kind of confusing. For Mac, see py2app.
I'm not aware of any specific Python GUI toolkits for Android.
Is wxPython Needed on the End  User's Computer