Apple Watch is already a great tool for tracking your health and fitness activity. You can now use it to plan or prevent pregnancy. The Natural Cycles app now uses temperature data from your Apple Watch. It uses a smart algorithm that analyzes daily hormone-driven temperature changes, so you will know when you are not fertile.
To get started, you simply have to wear your Apple Watch while you sleep and once your data is synced, you can open the NC° app to see your fertility status and ovulatory patterns. You can use the app with an Oura Ring or NC° Bluetooth thermometer.[where to get it]