Kalendarz PL is a free Android application developed by Alteris, which primarily focuses on providing a Polish calendar with public holidays, name days, and school vacations. This app is perfect for people who want to keep track of important events like weddings, celebrations, or meetings. Kalendarz PL also reminds you of name days in your family and friends, which you can directly call from the app itself.

With Kalendarz PL, you can easily enter and manage new events by entering basic information. The app also displays sunrise and sunset times and moon phases. You can place a small or large widget on the screen to show today's date and today's name day. The widget will also remind you of scheduled events in your calendar and your friends' name days.

The app also offers a Pro version, which you can activate with just a few clicks directly in the application menu. The Pro version provides even more functionality, including birthday notifications, additional widget styles, and more extensive settings options.

Please note that the app is in Polish language only and displays ads. However, in the Pro version, advertisements are not displayed.

Overall, Kalendarz PL is an excellent app for individuals who want to stay updated with Polish holidays, name days, and school vacations.