There are two packages available for NeonView. You will only need the first one to run NeonView, while the second one contains the source code:
NeonView 0.8.1 – Binary (Feb 27, 2013)
NeonView 0.8.1 – Source Tarball (Feb 27, 2013)
To compile NeonView, uncompress the source package and issue make && sudo make install inside the directory. You will need GTK+ 3 development libraries, make and gcc (sudo apt-get install libgtk-3-dev build-essential).