Is great, but it works by lowering the system volume during a call and (allegedly) raising it back up when the call is over. I have found, consistently that it does not raise my system volume back up and I start to miss alarms and alerts because the sound is basically off. This makes it impractical for me to use, though I hate the phone sounding alarms in my ear while I talk.

An alternative would be to actually find all active alarms/alerts, turn them off the same way you can with the alarm clock, then turn them back on when they call is finished.