Comment by ramses0

This is an alternate (probably similar) app to help your atomic clock watches get a signal from your phone rather than waiting for the vagaries of radio signal propagation (WWVB / https://www.nist.gov/pml/time-and-frequency-division/time-di...).

https://apps.apple.com/us/app/radio-wave-sync/id1484233572

...basically: Turn up your phone volume, wiggle the phone speaker (which has magnets), magnets == signals => watch gets the right time from your phone instead of remote radio waves.

I've used the app a few times before and it's generally pretty reliable if you follow the instructions!