I am making an iOS application that uses the user\'s google account to get data from his youtube account and show them .... first step is done using the gtm2 to authenticate
You are missing a =
in your format string.
Change
NSString *post =[[NSString alloc] initWithFormat:@"client_secret=%@&grant_type=refresh_token&refresh_token=%@&client_id%@",kGoogleClientSecretKey,kRefreshToken,kGoogleClientIDKey];
to
NSString *post =[[NSString alloc] initWithFormat:@"client_secret=%@&grant_type=refresh_token&refresh_token=%@&client_id=%@",kGoogleClientSecretKey,kRefreshToken,kGoogleClientIDKey];