It does not work on its own, but only as an addon to other Shelly Plus switches, in order to connect temperature sensors, humidity, etc.
I have had it connected to a Shelly Plus 1PM switch for a few months and connected to a DS18B20 thermometer, and it works flawlessly, providing continuous measurements.
Its use is for controlling the water temperature of a solar water heater and activating the resistance when the temperature drops below a threshold. However, there are also possibilities for programming the desired temperature (e.g. targeting a temperature of 40C every Monday and Wednesday from 07:00-09:00, while on other days and times targeting 35C).

I give it 4 stars instead of 5 for 2 reasons.
1. It is almost the same size as the switch, so it increases the volume of the switch significantly with this addon.
2. Temperature measurements do not automatically appear along with the switch in other integrations such as Google Home, but only if a virtual thermostat is created in the Shelly Application based on this measurement. Then, the thermostat appears in Google Home as a separate device and displays the targeted temperature as well as the measurement as "internal temperature".

PS: For someone looking for a solution for the same purpose, conventional Shelly switches have a load limit of 16A, which is not sufficient to power a classic 4KW solar water heater resistance. The solution to this is to use a power relay that supplies power to the resistance of the water heater, while the Shelly is connected to the control circuit of the relay and simply activates the relay without carrying the load of the resistance itself. The only problem with this method is that the Power Metering capability is lost, and the Shelly only measures the control current, which is very small.