The following code will help you to create your twitter account in your iPhone through coding. Also please note this code will only run in ios7 or later.

-(void)createTwitterAccount{

     ACAccountStore *store = [[ACAccountStore alloc]init];

    ACAccountType *twitterAccountType = [store

                                         accountTypeWithAccountTypeIdentifier:

                                         ACAccountTypeIdentifierTwitter];
    [store

     requestAccessToAccountsWithType:twitterAccountType

     options:NULL

     completion:^(BOOL granted, NSError *error) {





         if (granted) {
             ACAccount *account = [self returnAcAcount:store];

                 [store saveAccount:account withCompletionHandler:^(BOOL success, NSError *error) {
                     if (success) {
                         //
                     }
                 }];





             //  Step 2:  Create a request



         }


     }];
}

-(ACAccount *)returnAcAcount:(ACAccountStore *)store{



    //  Each account has a credential, which is comprised of a verified token and secret
    ACAccountCredential *credential =
    [[ACAccountCredential alloc] initWithOAuthToken:TWITTER_KEY tokenSecret:TWITTER_SECRET];

    //    

    //  Obtain the Twitter account type from the store
    ACAccountType *twitterAcctType =
    [store accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];

    //  Create a new account of the intended type

    //    ACAccountTypeIdentifierTwitter
    ACAccount *newAccount = [[ACAccount alloc] initWithAccountType:twitterAcctType];

    //  Attach the credential for this user
    newAccount.credential = credential;
    return newAccount;
}