Does not count properly for tax or visa purposes
Don't use this app for counting visa days, days spent in the schengen area, or for fiscal residence / tax physical presence tests. Quite simply the app doesn't properly count days for immigration, fiscal tax residence or physical presence tests. For example: look at a simple itinerary: you arrive to Country A on 5 June and then depart Country A for Country B on 10 June, and then travel from Country B to Country C on 15 June. For immigration purposes you would have spent SIX days in Country A, SIX days in Country B and SIX days in Country C. The app says you spent five days in each country and that is not how immigration calculates the number of days in a stay. If you are in and out of the schengen area, you could easily get caught up in an overstay of the 90-day / 180 day rule. Fiscal/tax residence and physical presence tests usually count only whole days, the app also doesn't get that right - using the above itinerary you would have four fiscal/tax days in each country, not five like the app indicates.