N'Ko (nqo) is shown as LTR in the list of languages on mobile web, even though it's RTL.
The probable reason is that it's not listed in src/mobile.languages.structured/rtlLanguages.js. It would be nice if it was automatically taken from the data in Messages*.php files, and I even have a vague recollection of patches that made it possible, but apparently it's not fully done yet.