Cloudsn stands for Cloud Services Notifications,it is a gnome application that check for new mails, feeds etc. It is developed for Gnome and tested in debian and ubuntu.
The providers check accounts against different services. Currently cloudsn has these providers implemented:
* GMail
* GReader
* Pop3
* Twitter

The stable version for Cloudsn for can be downloaded from here.
For Ubuntu 9.10 and later,use following three commands to install from PPA.

sudo add-apt-repository ppa:chuchiperriman/cloudsn
sudo apt-get update
sudo apt-get install cloudsn