Mask Timer helps you keep track of how long you have worn your masks and when its time to change them, be it when:• wearing the same mask continuously• swapping between surgical and FFP2/KN95 masks• wearing a mask occasionally, such as an FFP2/KN95 mask for when you go shoppingThe app helps you make sure you change your mask after 4 hours of total wear, which is the maximum recommended time. No more guesstimating when its been 4 hours.Simply add your masks, then tap the one youre wearing to track its use. When it expires, Mask Timer issues a notification to let you know its time to change it. Once its changed, tell the app and the timer resets. Its that simple.Mask Timer also allows you to configure the expiration time by mask type, from 1 hour all the way up to 8. Always follow your local regulations, and remember to change your mask if it is soiled or moist, even if you have been wearing it for less than 4 hours. FFP masks must also be replaced if they do not form a tight seal around your face anymore.