
Roque Lazarus
this is an excellent app with simple breathing exercise. it has help develop my breath holding capacity. it's important in emergency like underwater or in fire-smoke situation or if in need to run etc. it can built stamina in subtle instances without causing much discomfort.
11 people found this review helpful

Andreas Guntoro
Fake app. Oxygen level is checked through blood luminescence ( with camera and flash light ). This one is just a timer, not real.
28 people found this review helpful

Pearce Yuan
If without advertising it would be nice plus should add more information and describe for knowledge.
20 people found this review helpful