FINAL CUT - Library for creating terminal applications with text-based widgets
Padlet - Visual boards for organizing anything.
termbox - Termbox is a library that helps making terminal-based pseudo-GUIs.
BookWidgets - BookWidgets is an excellent application that let you create engaging exercises in minutes and easily share a varied variety of beautiful and fun activities with your classroom and others.
Slang - Slang is a powerful visual programming language using a newly developed stream-based paradigm.
Quizlet - Quizlet allows you to review and create flashcards for a variety of subjects, such as math and reading.