I thought that device on Calli's upper arm was called a heart monitor, but that tag is aliased to "cardiogram", which is a different device. There's no "heartbeat_monitor" tag. Do we need one, or is there a different, already-existing tag to use? Or, looking again, should it be tagged "cellphone" plus a new "pulse_rate_app" or "pulse_rate_display" tag or similar?