Breathing Coach guides you through the 4 7 8 breath, a well known technique by Dr. Weil that calms the mind and relaxes the muscles. It involves inhaling through your nose for 4 seconds, holding your breath for 7 seconds, and then exhaling through your mouth for 8 seconds. While 4 7 8 is the ideal ratio, people are different and may want to change it to better fit their needs. Customizing the ratio is easy: just say "customize" to begin the process, and Breathing Coach will ask you how many seconds you want for each step, or you can say "start" to begin with the normal values of 4, 7, and 8.
The exercise also comes in "quiet mode", where Breathing Coach will speak in a low, whispered tone if you're into that. Just say "start in quiet mode" to activate it.