Starting off with the functions, here's what it can do:
> Has an appealing GUI to make navigating with 5 buttons easily, and to save the OLEDs from burnout and increase the battery lifespan, it can go into light sleep automatically for a certain amount of seconds (only in GUI and time function)
> GPS function (shows you your coordinates, speed and altitude, the GPS time and date, and measuring the distance from point A to point B, as well as cardinal directions.)
> Main time/date function, along with the ability to sync up time with the GPS and or External RTC(coming soon) to the Esp32's internal RTC.
> Health functionality: Heartrate detection (uses an external sensor, see the pic of how it's used), and a pedometer for calculating the steps you took.
> Games: can play Tetris and pong for added entertainment.
> Utility function: Has a stopwatch that also has a way to keep laps of time as well as an adjustable countdown timer.
> Misc functions: A visual on seeing how the mpu6050 operates, and the temperature function that uses the small dht11 sensor.
> Networking: has a wifi scanning functionality (though you will need to restart it every time you're done)
> Settings: You can adjust the CPU clock cycle, adjust the sleep time, enable/diable wifi, and/or even turn off the second OLED to make the watch run smoothly!
So the first version used an Arduino Nano? Got any info on that one? Also, are you using the MPU6050 for pedometer tracking?