Downloaded for Systems I and II (in C) compiles code, cannot open .c files with it

I just downloaded this for my Systems I and II classes. I am disappointed to see a lack of great programs like this on the market. The $5 was well spent. I do have to copy and paste my C code into their system to compile, but it is not too big of a deal. It is way easier than downloading developer tools for xCode and typing gcc (file extension) -o (new filename) then ./(new file name) on the terminal to see your C code compile.

jpstiel about Espresso-C