cellwriter software package provides grid-entry handwriting input panel, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install cellwriter
cellwriter is installed in your system.
Make ensure the cellwriter package were installed using the commands given below,
$ sudo dpkg-query -l | grep cellwriter *
You will get with cellwriter package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | GNOME |
| Package | cellwriter |
| Version | 1.3.5-1 |
| Description | grid-entry handwriting input panel |
| Sub Section | GNOME |