Install iOS 12.1.4 If You Own the Apple Watch 4
If you bought Apple's new fourth-generation Apple Watch, and you skipped iOS 12.1.1, iOS 12.1.2 and iOS 12.1.3, there's a very good reason to install iOS 12.1.4 on your phone right now.
Apple's rolled out ECG support for the Apple Watch 4. If you're unfamiliar, it lets you monitor your heart health every day without having to carry anything extra or making an appointment to see your doctor.
Unfortunately, the only way to take an ECG on an Apple Watch is if you own the newest model, have iOS 12.1.1/iOS 12.1.2/iOS 12.1.3/iOS 12.1.4 installed on your iPhone, and have the watchOS 5.1.2 update installed on your watch.
If you have an older Apple Watch model you can still turn on irregular heartbeat notifications which will alert you to AFib (atrial fibrillation).
For more on how to take an ECG on the Apple Watch 4, watch the video above.