Casio VivCel VCL-110 Call Alert Digital Watch
If you’re old enough to remember a time when the cheap desktop speakers connected to your PC would make a buzzing sound when your cellphone started ringing, then you more or less understand the concept behind the Casio VivCel VCL-110. The watch had a built-in antenna that could detect when your nearby smartphone was responding to an incoming call from a local cell tower, and then start to buzz with an on-screen animation to alert you when you were about to get a ring. It was a weird concept for modern smartphone users whose devices rarely leave their pockets, but it provided a far more discreet way to stay in the know about phone calls while keeping a silenced phone out of sight.
