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.
UpNote - A beautiful and clean cross-platform app for notes organizer
allTags - allTags is a free, tag based file management application.
Notesnook - Notesnook is a simple and private note taking app that keeps your notes organized and synced on your phone, tablet and computer.
Tabbles - Tabbles use tags to organize and find files along with your colleagues.
todoZero - A powerful to-do and note app for busy people.