Ah, ok, that's a lot more clear, thanks. The first question I would have is "how long do you want to display the icon"? If I visit the page the next day, is the icon still there?
That said, the easiest and best way is to have, in any Entity that can be created and updated by a user, four attributes:
- CreatedOn - date/time when the record was created;
- CreatedBy - UserId of the user creating the record;
- ModifiedOn - date/time when the record was last modified;
- ModifiedBy - UserId of the user modifying the record.
When the user changes the values, and these changed values are saved to the database, the ModifiedOn and ModifiedBy attributes should be updated. Then, in your overview screen, you can check whether ModifiedOn is close enough to the CurrentDateTime() (e.g. using a DiffMinutes()) and if so, display the icon.