Apple’s newest smart watch is a stand-alone cellular device that packs a ton of new features, including a new dual-core processor that is 70 percent faster than its predecessor. Enhancements to the heart monitor include resting heart-rate and recovery heartrate data capture, as well as proactive notifications if unusual heart rates or heart rhythms are detected. All data will be captured as part of the Apple Heart Study, in cooperation with Stanford University Medicine. The new Watch OS 4 will enhance interactivity including access to 40 million songs through Apple Music and voice capabilities for Siri on the Watch for the first time. Perhaps most importantly, the case for the series 3 Watch is almost exactly the same size as the previous model. Despite adding cellular antennas, a new W2 chip for more efficient Bluetooth and Wi-Fi connectivity and an ambient microphone for cellular calls. Battery life is 18 hours. It will retail for $399, without cellular $329. It’s currently available.