http://wccftech.com/download-watchos-4/ >Apple has released watchOS 4 final version for all Apple Watch models, including Apple Series 2, Apple Watch Series 1 as well as Series 0. >From the looks of it, one might not expect much from software that powers a device as small as the Apple Watch. But if you lift the lid and see what watchOS 4 packs compared to watchOS 3, then you might just raise your eyebrows in surprise. Rather than throwing in a couple of features and calling it a day, watchOS 4 takes things further with changes in the right places. For those who love working out, they will be pleased to learn that a brand new UI has been put in place for them. But that’s not all, you can now track your high intensity interval training too with extreme accuracy, something which was not just possible before.