You can download Xournal with synaptic package manage. After installing it will be in the programs / tools menu.
(Note that I'm using hungarian ubuntu, so I'm just trying to translate the menu names :-))
To make the eraser tip to work go to the Options menu, and activate the "Eraser tip" option.
To make the pen button work as a highlighter go to the Options menu and choose highlighter in Button2 Mapping submenu.
You have to download these packages through Synaptic Package Manager before doing anything:
Compilation and Installation
Download the Xournal distribution tar.gz file, and unpack it. (it will be a folder)
Go to the folder in the Terminal and type:
sudo ./install-binary(and upgrade GTK+ and the other libraries if needed).
sudo make install
sudo make desktop-install
Configure error message:
If autogen.sh generates the error message configure: error: Library requirements (gtk+-2.0 >= 2.4.0 libgnomecanvas-2.0 >= 2.4.0 libgnomeprintui-2.2 >= 2.0.0) not met even though you have sufficiently recent versions of these libraries on your system, then you need to install some missing development packages.