I've yet to find a programmable watch that is competitive, but... I've been working on a DIY smartwatch firmware that uses the OLED version of the DSTIKE ESP32

I've yet to find a programmable watch that is competitive, but... I've been working on a DIY smartwatch firmware that uses the OLED version of the DSTIKE ESP32 watch development kit. This kit is less than $40 and is basically a small ESP32 dev board with a few LEDs and a mono OLED screen. It has the following features of use for a developer: 2.4ghz wifi, BLE, 2 cores and an interesting ULP core that can actually do a fair amount of logic (such as detect buttons) while still drawing microamps, A modestly accurate RTC that survives deepsleep, An internal white LED, which as packaged can be used as a reading light, A neopixel on the front, a square wave driven buzzer on the front, and a 600mah LIPO battery, and power management with discharge protection and . It is not by ANY means waterproof, but with some work (3d printing an enclosure and using a sealing spray) it can be modestly water resistant. At its price, you can actually buy more than 1 as backup in the event of serious water damage though. The predecessor to this was an ESP8266-based system (a much less capable chip) for mass wifi deauth attacks. It's a very interesting project writing a smartwatch firmwatch from scratch. Currently I'm trying to get to where I can use Rust (which I don't really know yet, so: learning opportunity) to write the core event loops I need. I won't be able to use Rust for the ULP cores (that has to be done in assembler) or OLED drivers, but I'm fairly sure the normal Rust binding generators will work fine. I highly recommend trying something like this if you have the time and inclination. It's very fun to incrementally add features to the watch.