CalendarSync is a tool that is used to sync appointments with a remote calendar. You can sync your appointments either with your own local calendar on your device, or with a remote calendar on a server. This is achieved by using the built-in APIs of Calendar.

The app is very simple to use, and you don't need to have any special knowledge to start using it.

To begin with, you need to install the app on your device. Next, you need to set up the server calendar that you want to sync with.

After that, you need to set up the syncing protocol that you want to use. You can choose between several protocols, such as HTTP, FTP, and WebDAV.

Once you have set up the server and the syncing protocol, you can start using the app.