Here is a Bluetooth thermometer that lets you keep an eye on your bath/pool water temperature. You can use the Ivation Bluetooth Water Thermometer in indoor or outdoor pools. It records the minimum and maximum daily temperatures. The companion app provides you with temperature data on your smartphone. The Ivation Water Thermometer connects to your smartphone via Bluetooth 4.0. Sets you back under $50 at this time.
Also check out:
[Source]
Disclaimer: *Our articles may contain affiliate links. Please read our disclaimer on how we fund this site. As an Amazon Associate, we earn from qualifying purchases.