stored procedure examples
I doubt there are many applications that are completely written in stored procedures. Doing a (sophisticated) user interface based on a procedural language in a DBMS is pretty hard to do (depending on the DBMS maybe even impossible). 

Oracle's APEX (APlication EXpress) is geared toward that, but the UI is still HTML - although it is generated generated through stored procedures if I'm not mistaken.

One application I know of that makes heavy use of stored procedures as part of the business logic is LedgerSMB: http://ledgersmb.org/