To install this plasmoid check if you have installed the needed header files (kdelibs and kdebase-workspace), 
unpack the archive, go to its directory and execute the install.sh script from a shell.

Alternatively you can go to the /applet directory and run the following commands from a shell:

mkdir build
cd build
cmake ../ -DCMAKE_INSTALL_PREFIX=`kde4-config --prefix`
make
sudo make install
kbuildsycoca4

After that done, the plasmoid should show up in the add widgets dialog.
If not, from a shell you can try to execute:

kquitapp plasma
plasma