the .desktop files are in
/usr/share/applications/hildon/
lists what is there. you can use grep to try to find something specific, for example
lists all with the word paper in it. I assume papertoss is one of them. once you have the filename you can do
that will show the contents of the file. There is a line starting with Exec=
and there is the command you use. Note that if the command points to something in /usr/bin you can just start that app with the last word in the command. For example the calendar.desktop file points to /usr/bin/Calendar so just typing Calendar from your home dir would start the calendar app.

When I want to launch an app from command line I usually try with just typing the beginning of the app name first and pressing tab to see if that command exists. Before going trough the trouble of looking at .desktop files.