Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Zenity - Zenity is a tool that allows you to display GTK dialog boxes in commandline and shell scripts.
Invision - Prototyping and collaboration for design teams
Glade - Glade is a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit...
Sketch - Professional digital design for Mac.
Yad - Yad (yet another dialog) is a fork of Zenity with many improvements, such as custom buttons...