If you are using Nextcloud and have apps like Bookmarks, Contacts, News, Notes, Tasks etc installed. You are in luck as you can install most of these apps from F-Droid on your Android phone.

I will make it quick, install F-Droid on your Android phone. Open the app and install the apps you would like to have it on your phone. Better to search by package name.

Nextcloud App F-Droid App F-Droid Package
Bookmarks Nextcloud Bookmarks nxbookmarks
Contacts DAVdroid davdroid
Calendar DAVdroid davdroid
Notes Nextcloud Notes owncloud.notes
Tasks Tasks dmfs.tasks
News News or OCReader owncloudnewsreader
Talk Talk nextcloud.talk2

Did i miss any? please share it in the comments section and i will update the post accordingly.