https://wccftech.com/watchos-5-3-released-with-ecg-support-for-canada-and-singapore-restores-walkie-talkie/

watchOS 5.3 is now available for download. It brings ECG support to Canada and Singapore users and restores the Walkie Talkie functionality too.

Apple has released the final version of watchOS 5.3 today and users in Canada and Singapore will be pleased to learn that they can now use the ECG feature in Apple Watch Series 4 right away. Furthermore, the Walkie Talkie feature has been restored in this release, which was previously disabled due to a security vulnerability. Here’s the complete changelog of the update: