iOS List of Contacts With Same App Installed

问题:

I'm looking for a way to create a list of contacts on iOS for people who have the same app installed. Maybe a way to sync Facebook contacts and send e-mail invitations to those contacts to install the app. The point is that I need some way to know which contacts on my phone have the app installed and I can't seem to find information on the different approaches to this.

Are there any APIs to help me? Are there multiple approaches to this? Where do I even begin to do this? Creating a list of my contacts is easy enough. Detecting which ones have my app installed is a different story.

回答1:

The only idea I have, would be to use a server. You transfer your contacts (best anonymized) to the server and there you can determine which contact also has the app installed. The server returns the result.

Basically all apps with a "contact list" I know of use this approach (e.g. whatsapp).

For the anonymisation check hash-functions.