Hi ,
We have implemented the custom salesforce login in our iPhone application, its working and we are getting a response like below format
"access_token" = "00D90000000zlFl!AQ8AQPivkCx4kUOaZfqjBLjH12CTy6wqV6SOx2FI99jsgdq3cE8Odnq7DGwUD7iP2CbleouktLET0EOgg10lf4qHG5Yzz6nI";
    id = "https://login.salesforce.com/id/00D90000000zlFlEAI/00590000003LHDxAAO";
    "instance_url" = "https://ap1.salesforce.com";
    "issued_at" = 1415788230586;
    signature = "QVL28zZsPewgtfcyh61hVZNx+REHrJ50jLlkzl8PP8A=";
    "token_type" = Bearer;

Once user is loggedIn we wanted to redirect him to salesforce home page (https://ap1.salesforce.com), so we have analysed and understnad that after custom login is sucess we need to load the "https://ap1.salesforce.com" URL in iPhone webview with the following cookies: sid & sid_Client.
I believe sid means access_token from the above response.
Can you pelase let us know how to get the sid_Client from the custom login service response.