Excalidraw - Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.
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.
Sketch Toy - A drawing application that lets you save and share replays of your work with friends.
Standard Notes - A safe place for your notes, thoughts, and life's work
Sketcharama - Draw a given word and let the other players guess your sketch.
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.