The application I envision will allow individuals to create attributes (key value pairs) which are assigned to profiles (named collection of attributes). They can then selectively share the profiles with others, when an attribute is updated the information may be shared with any of the profile subscribers.

The goal of this application is to reduce the headache of notifying everyone when some piece of your information or identity has changed. Every time I move there are a lot of places I need to notify, online and offline. When my debit or credit card needs to change there are many places that have the older account on file, some with automatic debits.

Having one local place where my information is stored securely and under my control, but allowing me to selectively share data with others, would resolve this problem. Presuming others wanted to use the application as well.