The best smartwatch should serve a number of purposes, with health and fitness tracking as the primary focus for most users. But the reason to opt for a smartwatch over a fitness tracker is enhanced interactivity with your phone through notifications, messaging and more.  The challenge with most of the smartwatches on the market is that they function best, or only function, with the matching phone. This is true of many of our favorites like the Apple Watch, Galaxy Watch, and Pixel Watch, but we’ll address options for those that use other phones or perish the thought of switching between iPhone and Android. Beyond compatibility with your phone, the main…