App for editing files in my Dropbox?

Solution 1:

You can use PlainText 2, it syncs with Dropbox (you can choose which folder to sync) and it let you choose which file extensions you want to sync.

Solution 2:

Nebulous Lite (there's also a non-ad-supported version) is a text editor for any type of file in Dropbox. I frequently use it to edit plain text files. I just tested it to sync and edit text files with a .org extension and it worked.

Solution 3:

The best comparison of text editors for iOS is the one started by Brett Terpstra found here :-

http://brettterpstra.com/ios-text-editors/

Unfortunately org-mode support is not one of the fields but the only one I've ever heard of is MobileOrg that you've mentioned.

You might find this blog post on using a combination of other software to implement an org-mode workflow useful.

http://www.osomac.com/2013/10/07/ios-workflows-org-mode/

His idea of using Drafts and Pythonista to do org-mode work is a good one.

My recommendation to you would be to have a good look at Editorial as it is a good editor with a Python interpreter and automation system behind it. You could probably hack together some good org-mode stuff in that. It is written by the same person that wrote Pythonista mentioned in the blog post above.

Personally I find myself using Drafts, Byword and Editorial for different purposes and all three have no problem with Dropbox.