While a Z-Wave controller will likely pair almost any Z-Wave device, not all Z-Wave device are compatible with ClareHome.
If a device includes as unknown, it may either be a non-compatible device or it did not completely pair. If it is a compatible device then the issue may be related to the proximity of the device to the controller. To remedy this you may need to insert additional repeating devices between the ClareHome controller and the “unknown” device.
Some devices are not controllable in the ClareHome app. Sensors are one such device. They interact with ClareHome by providing specific types of information from which you can trigger notifications or other actions. However by themselves, there is nothing to control.