Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
TagSpaces - TagSpaces is an open source platform for personal data management. With TagSpaces you can manage and organize the files on your laptop, tablet or smart phone.
Joplin - 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, tagged and modified either from the applications directly or from your own text editor.
TagFlow - TagFlow is an intelligent files manager that use tags for organize your documents.
Google Keep - Capture notes, share them with others, and access them from your computer, phone or tablet. Free with a Google account.
Tabbles - Tabbles use tags to organize and find files along with your colleagues.