Question about Smartwares SH5-Set-BS Radio

So a smartphone is not included, why should it be?
The transmitter is the switch, if you mean the receiver that receives the signal from the switch...
This is included because the set says: Replace the existing light switch with the flush-mounted switch actuator included in the scope of delivery and place the three wireless wall transmitters anywhere in the room. The light can now be switched on and off effortlessly from any wall transmitter. The set can be expanded at any time with the other Smartwares Smart Home components

So it must work on its own because it is expandable, but it is not a must.

I find it exciting that according to the text no receiver has to be placed^.^

of course i don't take any warranty for this statement because errors in product descriptions can happen, but returning the product is not a problem...