Welcome! My name is Valeriy Kovalenko, I’m a freediving instructor of Apnea Academy and the creator of the STAmina Apnea Trainer. I would like to thank you for using the app. It is the product of a beautiful team of professionals. I hope that you find it helpful and use it regularly to get better breath-holding skills. If after reading the documentation you still have questions, please feel free to contact me by email or on Facebook.