for me the out of sync happens during the transition between cycles. I think the problem is the visualization in this 4-7-8 app. you don't know when the exhale is going to end, you are almost at the end of exhale and inhale starts immediately. .There should be a small gap of 1 between the cycles 4-7-8-1-4-7-8-1 ... or the animation should indicate when the exhale is going to end.