You can import the header files for each Sharekit service that you wish to use. For example, if you have a page with a UILabel on it which has a string of text in it, you can import the services you wish to use at the top of your implementation file.
#import "SHKTwitter.h"
#import "SHKFacebook.h"
#import "SHKMail.h"
You can then set it to share via these services through any action you wish, i.e. the tap of a Facebook, Twitter, or Mail button? Or you can manually enter your own UIActionSheet with three items in for Twitter, Facebook and Mail which will then call the specific Sharekit service upon request.
If you wanted to post a URL for example;
#import "SHKTwitter.h" //include the service's header at the top of your class
...
// Create the item to share (in this example, a url)
NSURL *url = [NSURL URLWithString:@"http://iPhoneHelpr.com"];
SHKItem *item = [SHKItem URL:url title:@"Check out my site!"];
// Share the item
[SHKTwitter shareItem:item]; // Specify the specific service you want to share with
That is a simple explanation but it can be applied to share images, documents, strings of text etc.