If you’re an avid jailbreaker, then you’re likely familiar with the Filza file manager, which allows users to access their handset’s root filesystem and add, change, or delete existing files.
Filza comes with a lot of features, including a plain text file viewer, but with a newly-released and free jailbreak tweak dubbed FilzaPlus by iOS developer Skitty, you can add a full-blown code editor with syntax highlighting to that list.