Do you want make DIY watch? No problem. This is DIY project watch's. OLED display, ATmega328P, RTC DS3231M. Display has resolution 128x64 pixels and 1.3". The watch is powered from LiPo battery. The watch can be powered from USB. You can play games and the watch contains alarm.

http://blog.zakkemble.co.uk/diy-digital-wristwatch/