Mingwear 1.85-Inch Men's and Women's smartwatch fits for Android and iPhone Devices with Fitness Tracker, Pedometer, Answer/Call/120 Sport Modes, IP68 Waterproof Fitness Watch（black）

I'll be honest, I use the app connected to this only enough to get the time accurate and adjust settings, then uninstall. So I can't speak to how it works as a truly smart watch. However, for my purposes, it works wonderfully. I use it as a step tracker primarily, and secondary functions as HR monitor, 02 sat, and stress (HR variability), which isn't medical grade but satisfies my curiosity. I also found that the "breath training" tool is much improved over the previous model.