Build a mobile personal relationship assistant.
You can add new contacts in there, and the frequency you want to catch up with them. The app shows you the upcoming people you should contact.
It will help people build and maintain their social network. Create the app using html5/js so that people can use it from anywhere.
Example:
Robert -> Due
Jenny -> to contact in 3 days
Arthur -> to contact in 4 days
Matt -> to contact in 10 days