In a JAMA Viewpoint, Christopher Bonafide and colleagues discuss the efficacy and safety of smartphone apps integrated with sensors that monitor infants’ vital signs. While the performance characteristics of these sensors are unknown to the public and the regulations around them are scarce, their sales have skyrocketed, reaching 40,000 units for a single brand of “smart sock” monitors. These companies use direct-to-parent advertising to portray their products as necessary to alert parents when something is wrong with their infants’ cardiorespiratory health, even though there are no medical indications for monitoring healthy infants at home, as stated by the American Academy of Pediatrics. In fact, the makers of consumer infant physiologic monitors have avoided the FDA medical device regulation as well as safety, accuracy and effectiveness studies by not making claims that the devices prevent, diagnose or treat Sudden Infant Death Syndrome, and instead focusing on making parents able to better monitor their infants. Moreover, even if consumer monitors were highly accurate, the clinical appropriateness of monitoring health infants would remain in question, as false-positive alarms due to artifacts and even true-positive alarms that are not clinically important may lead to over-diagnosis. There is no evidence that consumer infant physiologic monitors are life-saving, and there is potential for harm if parents choose to use them. Child and family advocates should make it clear to the FDA and policy makers that regulatory guidance and research evaluating the safety, accuracy, and effectiveness of these products are needed.