Install input-pad by entering the following commands in the terminal:
sudo apt update sudo apt install input-pad
Description:
On-screen Input Pad to Send Characters with Mouse
The input pad is a tool to send a character to text applications when the corresponging button is pressed. It provides the GTK+ based GUI and can send characters when the GTK+ buttons are pressed. . This package contains a standalone application.
Homepage: http://code.google.com/p/input-pad/
Version: 1.0.3-1build1
Section: universe/utils