Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Sketch - Professional digital design for Mac.
YouiDraw - Draw and Design Vector Graphics, Logo, Text, icon in the Cloud.
Invision - Prototyping and collaboration for design teams
UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.