Mailnag is an email notification application for Gnome 3. I'd been using it in Fedora but couldn't get it working in Debian Wheezy. Some of the listed requirements didn't seem to be available in Debian. Today I wondered if the requirements listed on the Mailnag page might actually be available under a different name in the Debian repositories, and indeed they were. Here are the requirements listed on the Mailnag page, and how they appear in the Debian repository, at the time of writing at least.
pygobject-3 = python-gobject. Installed in Wheezy.
gir-notify = gir1.2-notify-0.7. Missing in Wheezy- install.
gir-gstreamer = gir1.2-gstreamer-0.10. Installed in Wheezy.
python-httplib2 (same). Installed in Wheezy.
python2-gnomekeyring = python-gnomekeyring. [Update: Not] Installed in Wheezy. [Install- not sure if I missed this or the package has been removed.]]
pyxdg = python-xdg. Installed in Wheezy.
gettext (same). Missing in Wheezy- install.