[Mattia] decided that a spare key card might be good to have around, and that building it into his Casio F-91W watch would put the key as close at hand as it could be without getting an implant.

[Matteo] has been a fan of the Casio F-91W wristwatch virtually since its release in 1989. And not without good reason, either. The watch boasts reliable timekeeping and extremely long battery ...

Both watches run PebbleOS, which Migicovsky and others pushed Google to make open source late last year. Therefore "most of ...