Launch OS X Apps in a Specific Language?

# Permanently 
$ defaults write com.apple.iTunes AppleLanguages '("ja-JP")'
$ defaults write com.apple.iTunes AppleLanguages '("zh-CN")'
$ defaults write com.apple.Maps AppleLanguages '("zh-CN")'
$ defaults write com.tencent.qq AppleLanguages '("zh-CN")'
$ defaults write com.tencent.xinWeChat AppleLanguages '("zh-CN")'

# Just once
$ /Applications/Maps.app/Contents/MacOS/Maps -AppleLanguages '(zh-TW)'

Update Aug 25, 2016: This may not work for all apps.