Box Breathing - Breathe in sync with this to calm yourself down
Othership - Othership offers 500+ music-driven guided breathwork classes to lift you up and ground you down: kickstart your day, cultivate focus, fight fatigue, sleep deeper, regulate your emotions, and learn the science-backed how + why of breathing mechanics.
QuietKit - Guided meditation for beginners (for free)
Breathe2Relax - Breathing exercises to practice diaphragmatic breathing.
MindfulDevMag - Mindfulness for Developers Magazine
Breathing exercises - Breathing exercises to calm down and practice diaphragmatic breathing.