This app can be used to train your breath.
There are two modes (CO2, O2) which differ in what they attempt.
CO2 practice tries to increase CO2 tolerance by decreasing the time between
O2 practice tries to increase O2 capacity by increasing the duration of apnea
Preparation / apnea time refer to the initial duration of the corresponding set.
Increments determine the change between each set (depending on the chosen practice).
Sets are how many preparation / apnea cycles are performed.
This website was built for fun after not finding any free options for this exact purpose.
Code is open sourced on GitHub and if you have any improvements feel free to make a