If you love IPython Notebook, you probably find it annoying that there is no standalone offline app to open .ipynb files. You need to open a terminal, switch to the folder, and exec a command.
This simple app can be useful for you.
sudo add-apt-repository ppa:tartavull/ppa
sudo apt-get update
sudo apt-get install inotebook
It will download all the require dependencies like ipython
Double click to directly open a file