How to sync Notes Writer across my devices?

There is a special location named “In iCloud” in the “Locations” main view of Notes Writer. On your iPad/iPhone, if you copy or create documents/folders into that folder or create new documents (or folders) there then they will appear automatically in the “In iCloud” location on your iPhone (check the iCloud Drive location on your computer as well) and vice versa. You have to set up the same iCloud account in your “Settings” iOS app on both devices.

You can also use other cloud services like iCloud Drive, Dropbox, Google Drive, Box or WebDAV.