Knotable - Cut the noise out of busy email threads
Standard Notes - A safe place for your notes, thoughts, and life's work
Indigrid - Plain text outliner with side-by-side views.
Alternote - OS X note-taking app for Evernote.
Google Drive - Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Writer - Writer is a mobile app on Google Play featuring the idea of surpassing the complicated interfaces of other traditional word processors. It encourages the use of taking notes or writing whatever it is you may desire on your phone or tablet.