I have a student project, an application to track user expenses. You can create many users, each user can create a group, add necessary users to the group and then for each group create any number of expenses. There are some other functions available and the application is ready and working.
The task is to apply two design patterns to this application and I have no idea what patterns I can implement in this case (except the obvious Singleton pattern to create only one instance of database communication class).
If you have any experience or fresh knowledge of Design Patterns it would be a huge help if you can point me in the right direction.