confidential.tech is described as 'Tag or auto-tag your files along with your team,on your hard-disk, on shared drives or in the Cloud and visually spot them while browsing. Tag and organize emails: Outlook will warn you when sending something you shouldn’t' and is an app in the Office & Productivity category. There are more than 25 alternatives to confidential.tech for a variety of platforms, including Windows, Online / Web-based, Android, iPhone and Mac. The best alternative is Joplin. It's not free, so if you're looking for a free alternative, you could try Microsoft OneNote or Evernote. Other great apps like confidential.tech are TagSpaces (Freemium, Open Source), Cryptee (Freemium, Open Source), Notejoy (Freemium) and Tabbles (Freemium).
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.
Tag files, along with your peers to organize and find them. Works on local or network drives and in the Cloud. Tabbles features collaborative tagging, auto-tagging rules, an Outlook Plugin, a Chrome extension and is well integrated with Windows,.
Keepmark allows you to organize your files, documents, emails, bookmarks, tasks and generally - resources. Its also an efficient solution for finding your resources by names, meta-data and document content.