I add a PPA but the software does not show up in Ubuntu 11.10 updates nor Software Centre

Every time I add a PPA I cannot see the package I'm trying to install. I suppose I must be doing something wrong! So here's my latest effort:

In a Terminal I typed:

sudo add-apt-repository ppa:jeromerobert/misc

and that seemed to work correctly

Then I typed:

sudo apt-get update

But when I go to Synaptic or Software Center the application I want to install is not there. Could someone please tell me what I'm doing wrong?