A free program for Android, by GalleryApp.

CountdownCalendar is a useful app that helps you plan for the future. It has a simple interface and a lot of options.

CountdownCalendar has a list of all the upcoming events. You can add a to-do list and set a deadline for it. It also has a list of all the events that you have already attended. You can mark the ones that you have done as finished.

You can also travel, present, or do business abroad. It has a calendar that you can use to find out what day you have to go to work or to school. It also has a list of all the holidays that are going to be held in the year that you are going to be born.