If you want truly standalone + WiFi + custom code, check SQFMI Watchy (ESP32). You can flash your own firmware, call HTTPS endpoints, parse JSON, and render custom UI without a phone in the loop.
Main tradeoff: it’s very DIY (power management, UX polish, tooling). If you want less DIY, Wear OS gives a better SDK, but the platform lock-in is much stronger.
Main tradeoff: it’s very DIY (power management, UX polish, tooling). If you want less DIY, Wear OS gives a better SDK, but the platform lock-in is much stronger.