there were a few. as far as I remember none of them every got finalized even though at least one of them worked pretty well.
look in MOD in development for 3.0
there is nothing currently that is working for 3.1 as an extension.
I'm baaaaaccckkkk. still doing work on donation basis. PM your needs.
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If a tree falls in the forest and nobody is there, does it make a sound?