Mobile Multi Platform custrom tracking AR plugin

I'm searching for a AR plugin only to track custom markers (In this case, custom images, not QR codes).

This is the only feature I need on the Plugin...

I know there's Vuforia or Metaio, but none of them targets Windows Phone 8.

Does anybody knows a AR plugin which also targets Windows Phone?

Another option is to find a windows phone "only" solution... And rewrite the code only to give support to WP...

(this is a Requisite because in my country, WP market share is almost 2x the iOS market share)