I live in an older house where each room has an electrical baseboard heater connected to its own thermostat. Is there hardware/software to control all them from one place? For example a hub with an app. Ideally I'd like a control mechanism whereby I can set the temperature to drop while no is home and rise back up 30 min before we get back. I assume the old fashioned alternative is for me to rewire all the heaters but even then I'm not sure the circuit could handle the power draw. What's usually done in such cases?
Since you have an Aube TH108, you will need a line voltage thermostat. They do make smart thermostats and wifi connected thermostats capable of switching line voltage.
If you want something like a Nest or EcoBee, you'll also need something like an Aube RC840T-240 to provide the 24 volts they expect and act on the low voltage signals they provide.
The question really isn't if it could be done. The real question would be is it feasible or cost effective?
First as longneck has pointed out what is the make and model of the units? Many of these base board heaters thermostats are made to keep costs down, therefore opening up the control wire may damage the unit beyond repair.
So then the only feasible way I can think of would be to take control of the power side of the wiring. That would require relays such as a RIB (relay in a box) type. and some sort of a main control thermostat and/or a microprocessor type control unit.
Then you could use the primary T'stat to turn the circuits off and on and the internal units in the baseboards would kick in on a preset temperature.
As far as an app or a small system is concerned. You have to have a market to justify manufacturing and I don't know of any one who would do that. So I am guessing it would have to be custom made (expensive).
Hope this helps.