Over the years, it has been incredible to learn how taking control of the way we breathe has had a huge effect on our mood and body. We try to practice regular breathing exercises to get in to a specific state of mind; destress, calming down, sleeping, focus, boosting alertness.
Some of the tools we have found very helpful, come in the form of two different apps: oak and apnea. Oak is basically a meditation app, but has a very useful breathing part added. Apnea is actually an app meant for free divers, but will focus your breathing. If you go for the extended exercise tables, it also has the side effect of improving your lung capacity.
Check them out here: