Incorrect ratios!!
This app is good if you down load the full version for making your own ratios. The issue with this app is that the ratios given in the free version and the full are incorrect. You would have to change the retention on the exhale to advanced and retention on the inhale to beginner. basically, inhale, retain then exhale, "beginner". Advanced would be, inhale, retain, exhale, retain. For the price you pay, you do not get guidance on Kapalbhati, Bhastrika, sheetali, seetkari and a basic ujjayi pranayama.
Drpawe about
Universal Breathing - Pranayama