Many applications that I develop need to be translated and so we work with translators and normally the flow of work is something like:
# Prepare strings files (.po or other formats)
# Send the files.
# Receive translations.
# Found a change, repeat 1 to 4.
# Kill myself doe a overflow of translations files (minimized / maximized because we added the date to the file name).
It could be very nice to have a phabricator application that let developers upload its strings to be translated, and to translators change its translations and even do it online (like launchpad).