slightly off topic: I stuck a NFC chip on the doorpost to my shul (near the mezuza lol) - when users tap their phone to the chip it silences everything, disables GPS, WIFI, Bluetooth etc (to conserve battery) and a notification pops up saying "Kavana Mode Enabled"
When leaving the shul, users tap it again to re-enable everything etc...
I encourage others to program chips like this as well (takes 2 minutes) - really helps in a "businessman's" shul