Not specific to the columbus or cincinnati user groups, but still thought I'd pass along. It might be a good thing to speak about a kotlin/android related topic here.
http://chicagoroboto.com/
I wouldn't be surprised if had a few ohio folks being so close and last year looked like a pretty awesome conference with some other great speakers. It's run by some of the same folks who run 360AnDev, iDev and a few others.
The RFP is open now.