Can the Netatmo Smart Thermostat function without app setup?

Hello, I don't own the Netatmo Smart Thermostat yet.

In the event that for example the app is not supported anymore (in the future), and I would do a full reset of the thermostat en relais. Would it then be able to function as a dumb thermostat? (just 'live' temperature up and down)? That is the thermostat we have now from Honeywell. 

I would have some piece of mind knowing that in worst-case scenario it would be a dumb thermostat, and not a brick. 

So during the first setup, can you make it work keeping a single set temperature without wifi or using the app? Or would the thermostat complain / not work? 

Thanks!