Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor.
Notion is a versatile tool that streamlines collaboration and organization within teams. It is similar to Google Docs, allowing team members to access and contribute to content in real-time.
Cryptee is a safety and privacy focused, encrypted and cross-platform personal data storage service. You can write personal documents, notes, journals, store photos and all sorts of other files.