My question is what IDE is the best to download for my Galaxy note 5 ?

Question

I need an free version !

Answer 1

There isn't much...
But you can find some more or less advanced text editor.

Else, the once I've experiement is for Python, and named QPython... ( in an integrated app, you can edit and run your Python code, and he's provide usefull library as kivy for graphical interfaces, or bottle for web serving )