1、Support most all of the platform, for example, iphone ,android ,wm, etc.

2、Main functions: with this pogram you need to login to update contacts. if your friends updates a new phone number,the next time, when you open the program, it will notify you that somebody updated their phone number.

3、the most ideable method is to integrate the program to default sys contacts.

4、the other thing we should thing is that protect users' privacy.