Invite all friends option in facebook and gmail?

In my iPhone application, i want to support invite all friends in facebook and gmail contact list my pressing "Invite all facebook friends/gmai开发者_如何学Pythonl friends" button.

Does facebook and gmail provides APIs to support this functionality in iPhone or web?

Is there any problem in submitting this app to appstore, will apple treat this as SPAM?

You can use Facebook Graph API where you can find all lists of your friends. Refer this link

http://developers.facebook.com/docs/reference/api/