For Free: go to
http://www.thestreamcenter.com/pda/ choose MO and scroll down....105.7 is there. It will stream through WMP or TCPMP if you use it instead.
Or, if you want to pay for an EXCELLENT app, buy Kimona Play. Choose Kinoma Guide, scroll down to radio, and select tuned.mobi. Select US, select Missouri....and there it is.