We need proper support for plurals in some string translations on the Wikipedia native mobile apps; I'm currently looking at the AndroidFFS import/export module and trying to figure out how ready that is, and looking into how to improve the AppleFFS import/export module for iOS/OSX projects.
Android has native plural strings support allowing for a separate complete string for each plural form. AndroidXmlFFS in Translate has some sort of import/export conversion into something like '{{PLURAL|one=foo|others=bar}}' in the messages exposed to translators, but plurals are not used in the new Wikipedia Android app yet so I see no live examples. There are a few plural strings in the Android version of the Commons app we did last year, but those strings do not appear in any of the localizations and I can't find them in TWN, so I'm worried that the import of plural strings from the 'strings.xml' doesn't actually work.
Also, the format the AndroidXmlFFS module uses doesn't quite seem the same as what MediaWiki uses ('{{PLURAL:$1|foo|bar}}'). Is that going to be confusing for translators, or should we change it to look more like the MediaWiki form? (Does this require mapping positional parameters to plural form names, or are they always in a known order?)
iOS 7/OS X 10.9 also has a 'native' way of handling plurals which requires a second '.stringdict' output file alongside the '.strings' file; or there are CLDR-powered compatibility libraries like https://github.com/Smartling/ios-i18n which embed multiple message alternates in the main '.strings' file.
I could rig up an import/export filter similar to the Android one (or maybe share the actual list<->parser function conversion code), but first I want to check if it works and if it's what the translators expect to work with...
-- brion