Existing Honeywell relay - new Netatmo thermostat

Hi there,
We live in a house where a Honeywell Home wireless T87RF2025 is installed to an Intergas Kompakt heating system. The relay is placed above a ceiling and we cannot reach it unfortunately. As we rent the house we need to put it the working thermostat back when we stop renting. 

However we would like to have a thermostat that has a setup with a weekly program and manual adjustment. An app connection would be nice but not necessary, connection to Apple Home or such is absolutely not needed. 

Could we connect a Netatmo thermostat to the existing Honeywell relay? 

Which models would be compatible (an url link to the shop would be helpful)?

We have an Intergas Kombi Kompakt HRE with it, and I found that it has a modulating option.
Thanks much for answering! 

Ps.Could the model below work?