Open Peeps - A hand-drawn illustration library.
Workflowy - A better way to organize your mind.
Control Illustrations - 108 free flat illustrations with customizable characters
Dynalist - Dynalist is a web app that lets you break down and organize your thoughts in the format of lists.
DrawKit - MIT licensed SVG illustrations, in 2 styles
SuperNotecard - Introducing SuperNotecard. SuperNotecard is an online writing tool that features virtual notecards to help arrange facts or scenes, track details, organize paragraphs, and clarify your composition process.