I do have a question...

What type of files are allowed? .8xp files with raw data, or text files with ASCII Chars as data? If so, how do I input the data? .db $FF ?

I don't mean to be rude, but I want to use this. I just don't know how...

This program will take the raw data from any kind of file and put it in an appvar. The extention does not matter. If you have a power point presentation under 64k you want to convert to an appvar you can do that It will just copy all the bytes. The only thing my program does is generate the headers for the appvar and write it all to a new file.

To input .db $FF you get a hex editor and make a new file with $FF in it. Just one byte. Open the command prompt and change directory. Now run my program like this:
to8xv yourfile.ext appvar.8xv TESTVAR

Now try to send appvar.8xv to your calculator to test it

I would suggest adding a readme to the repository outlining how to use the command line tool. As well as outlining how to use the ti83f.py module in your own code.
Another good thing to add to your code would be docstrings.