indicator-messages software package provides indicator that collects messages that need a response, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install indicator-messages
indicator-messages is installed in your system.
Make ensure the indicator-messages package were installed using the commands given below,
$ sudo dpkg-query -l | grep indicator-messages *
You will get with indicator-messages package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | GNOME |
| Package | indicator-messages |
| Version | 0.6.0-1 |
| Description | indicator that collects messages that need a response |
| Sub Section | GNOME |