HowLong is a great app that will calculate how long something is.
We can find out how long we live, how many hours, days, months, years. We calculate how long our relationship with another person lasts. We will find out how long we have our phone, how much is our car, TV, washing machine ...
In free version:
We can set three dates for the function: how long.
We can set three dates for the function: countdown to the event.
Contains an ad at the bottom of the screen.