New version is ready, I have some trouble publishing it to apps.mios.com
Until then, just install the current version from apps.mios.com and you can then manually update the luup files in UI5 through Apps -> Develop Apps -> Luup files.
The most recent files can be found at http://dijkstj.home.xs4all.nl/icy/icy15.zip
which included an updated icon and temperature setpoint control.
The icy thermostat is now also supported in the latest beta of the iOS HomeWave app!