asciiflow - Infinite ASCII diagrams, save to Google Drive, resize, freeform draw, and export straight to text/html.
Playscii - Full-featured ASCII art and graphic editor and game creation tool
Lekh Diagram - Lekh Diagram empowers you to express your idea on iPad and iPhone simply by sketching shapes with...
PabloDraw - PabloDraw is an Ansi/Ascii text and RIPscrip vector graphic art editor/viewer with multi-user capabilities.
Core2D - A multi-platform data driven 2D diagram editor.
REXPaint - REXPaint is a powerful and user-friendly ASCII art editor.