I'd start with messaging the admins of the various Facebook groups dedicated to mobile game development and asking if they'd be willing to 1) enable you to put up a post about the SDK, and 2) pin the post for a week so that you get a bit more visibility within those communities. You can also find the appropriate thread on the various mobile gaming forums and chime in there. I would recommend trying to be helpful 9 times before you ask for something once. You'll notice a much better response if you've become an active contributor to each community before you start selling your stuff, no matter how soft the sell and no matter how valuable the stuff.

Hope this helps,
Austin