letterize software package provides 1.3-5, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install letterize
letterize is installed in your system.
Make ensure the letterize package were installed using the commands given below,
$ sudo dpkg-query -l | grep letterize *
You will get with letterize package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | Miscellaneous |
| Package | letterize |
| Version | 1.3-5 |
| Description | 1.3-5 |
| Sub Section | Misc |