A monitoring and signaling system is provided that may include at least one safety device for a vehicle which can be coupled to a seat for infants or to an item for the boot for pets or to a pet collar, configured to generate an output signal indicative of the presence of an infant or a pet on the seat or in the boot or of the fact that the pet wears the collar. The system may further include a first signaling device configured to emit first signals in sequence when the output signal indicates the presence of the infant or of the pet in the vehicle; and a second signaling device configured to emit second signals in sequence when coupled to the vehicle. The system may further include a mobile device configured to: receive pairs of signals each formed by a first and a second signal, make determinations based thereon, and generate, based on the detection, different monitoring signals.