This codes consist of 3 java source code file, 1 R.java, 4 xml design screen file, and some other files. I will let you know each of file description in a brief.
R.java is a generated class by android when we compile our source code. it contains all constant use in xml design screen, its id, layout, style, styleable, and any other.
Contact.java is main activity, it display contacts taken from database with the wrapper of database function (DBHelper -DBHelper.java).
ContactEdit.java is an activity to edit /add new contact. when you choose to add new contact from menu, Contact will call ContactEdit screen, and waitting for it. After finish, the contact added, will be shown at the contact list.
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