Right now I always carry my N900 and a notebook. As soon as the page buttons are done I'll need only the N900! I tried the Debian version but it isn't as cool.
Xournal it's written in C and yes you can help.
Now I'm at work, later tonight I'll post a link to GIT source codes and can point out some hints on where to look.
How are your Hildon/GTK skills?
I can't seem to annotate PDFs anymore.. the program just crashes (I'll attach terminal output later). This is from the latest extras-devel build (tried a uninstall and reinstall)
I think you are suffering from the same issue I am having.
Whenever I try to open the File Manager dialog it crashes.
I didn't touch anything to Xournal and me, you and another user have the same issue.
I really have no idea of what is going on here...I'll have to investigate deeper.
I will have some time this weekend. I don't really need a full git repo. You could just tar it up and email it to me. My (spam protected) email is q s t r e a m AT g mail. com.