open iBooks from my app

Question

I have some PDF in my app. I want to provide an option to open those PDF in other third party e-readers app that might be installed on the device, like Stanza and iBooks. Dropbox application has successfully implemented this feature and I can't find any information on how to detect what other e-readers are available on the device or what the custom url scheme is for those apps. Any help would be greatly appreciated. thanks in advance guys.

Solution

iBooks

NSString *stringURL = @"itms-books:";

NSURL *url = [NSURL URLWithString:stringURL];

[[UIApplication sharedApplication] openURL:url];

NSString *stringURL = @"itms-bookss:";

NSURL *url = [NSURL URLWithString:stringURL];

[[UIApplication sharedApplication] openURL:url];