LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
UpNote - A beautiful and clean cross-platform app for notes organizer
draw.io - Online diagramming application
Notesnook - Notesnook is a simple and private note taking app that keeps your notes organized and synced on your phone, tablet and computer.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Note Board - Productivity app. Save information like a sticky notes.