Here is a sequence diagram for a recipe sharing and meal planning app: User -> App: Opens app App -> User: Displays home screen User -> App: Selects "Create Account" App -> User: Displays registration form User -> App: Enters registration information App -> User: Validates information App -> Database: Saves user information App -> User: Displays login screen User -> App: Enters login information App -> User: Validates login information App -> User: Displays recipe search screen User -> App: Enters search criteria App -> Database: Searches for recipes matching criteria App -> User: Displays list of matching recipes User -> App: Selects a recipe App -> User: Displays recipe details User -> App: Adds recipe to meal plan App -> User: Displays meal plan User -> App: Edits meal plan App -> User: Saves changes to meal plan User -> App: Logs out App -> User: Displays login screen Note: This is a simplified sequence diagram and may not include all possible interactions or error handling.