For me it is a convenient and compact tool in which I can put all my ideas, goals, thoughts
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
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.
Buku - A powerful command-line bookmark manager.
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.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Google Keep - Capture notes, share them with others, and access them from your computer, phone or tablet. Free with a Google account.