A new dutch thermostat is currently being released which is fully opentherm compatible and even got a api for remote controle.
Link to website for more info: http://www.thermosmart.nl/
I hope someone could take a look and see if a app could be made to control this thermostat, a full api documentation is also available for those who are interested, see here the api documentation: Loading...
Hope someone is interested to develop something for it 