We also offer Java APIs that make it easy to work with WireframeSketcher files. So in theory such a tool should be possible to write, although you should check that Axure and JustInMind have a clearly documented format too.
John Galt03 Mar 2015
Thank you, Peter!
Thank you for your answer, I'll try to do something with it )
P.S. But if someone will find a ready solution, I'll be glad if he will share a link to it here )