Adding Dual-Language Support to Posts

Hello all,

I have a large site and we’d like to slowly start translating some of the site into Spanish. Is there a good method or plug in to creating a language switch for specific posts – not the entire site. I’ve looked at the plug-ins like xili-language and Language Switcher, but I’d like something that does something like this. If a translation exist, a flag could appear next to the post link, post preview or the post itself that would switch that content to Spanish. Thanks!