Although it has a rather simple, straightforward title, this is one of the best code editing apps that I have used thus far—and I have tried A LOT of them. It supports syntax highlighting for a ton of different programming/scripting/markup languages and file types and for those of you with keyboards that include additional control keys, i.e. cut/copy/paste, tab, home, end, etc., this app handles them all with no issues. Honestly, there is only one tiny thing that I've encountered so far and it's just a very slight "inconvenience": when using the search feature (find, find/replace), your search text is displayed in the top bar along with previous/next arrows. After modifying your search text and pressing the search button again, your previous search text is still displayed in the top bar and those arrows will still find that text instead of your new search text. All you have to do is press the "back" arrow in the top left corner to remove your previous search, then open the search dialog and press search again. Aside from that, this app is awesome. I highly recommend trying it out.
