As far was wearables are concerned  there seems to be no age limits to their actual use. I’ve seen monitoring devices for grandparents in their 80s and fitness monitors for stressed out 25+ wannabees. Now babies are targeted, and of course their worried parents on Wi-Fi 24/7/366.

Sproutling is a fully-featured baby monitor promising to ease the apprehension of bringing up baby by not only streaming critical data like heart rate, skin temperature, body position and motion to any iOS or Android device, but also pre-preparing parents (!) with handy info like what time the little tyke's going to wake up and whether he or she is likely to be cooing like a cute thing or grumbling like a bear with a sore head. The sensor even measures sound levels.

The Sproutling straps to the baby's ankle and is recharged using the supplied induction dock. I was unable to find any indication of the baby-2-parent transmission method used (Bluetooth; baby-level Wi-Fi??), skin allergy risks, and some other concerns. Sproutling is currently sold out but their website says you can sign up to a waiting list. I did not see any indication though of delivery within 9 months of ordering.