Displaying a message in iOS which has the same functionality as Toast in Android

You can make use of MBProgressHUD project.

Use HUD mode MBProgressHUDModeText for toast-like behaviour,

MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.navigationController.view animated:YES];

// Configure for text only and offset down
hud.mode = MBProgressHUDModeText;
hud.label.text = @"Some message...";
hud.margin = 10.f;
hud.yOffset = 150.f;
hud.removeFromSuperViewOnHide = YES;

[hud hideAnimated:YES afterDelay:3];