The next two apps that you might want to use are the Calendar and Contacts, often collectively known as “groupware”. The calendar gives you the ability to create and manage events, while the contacts app is able to store phone numbers, e-mail addresses and other personal information about your friends and family. Both of these are able to be synchronized to your desktop computer and your mobile device as well.
LibertyStratus is a cloud platform for file storage and synchronization, calendaring and contacts, productivity tools and more. It is based on an open source project called Nextcloud, which is used by individuals, companies and governments a round the world. This means that any information that you find that applies to Nextcloud, generally also applies to LibertyStratus.