It's funny to read what people think are beautiful apps here.
IMHO, the most beautiful software are always games and entertainment titles... After all that is the purpose.
Office 2013? It's very useful! I use a classic menu template and got rid of the ribbon, since the functionality is the same, but in my preferred format. Beauty does not come into play with office...
I can use it for creating beautiful PowerPoint and excel spreadsheets.
Code is never 'beautiful'. It's either concise, well-written and formatted well, or it isn't.