I've been using a hacked (but genuine) Casio F-91W. The same I was using when I was 14.
Last time I was so happy with a piece of tech I've bought was with my Miscrosoft Surface.
This watch beeps every hour, and this helps me SO MUCH to keep track of my day. It costs about 10 EUR on Amazon Deutschland or about 20 USD.
Make sure to buy the genuine one, there are tens of rip-offs.
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Mine has an RFID antenna and a storage chip to send data via RFID. Also has a black background LED (inverted polarity)
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