animate footer up

footer.m

UIView *footer;
    
// position the footer below the screen, out of sight
footer.frame = CGRectMake(0, CGRectGetHeight(self.view.frame), CGRectGetWidth(footer.frame), CGRectGetHeight(footer.frame));
    
// animate the footer up from the bottom of the screen
[UIView animateWithDuration:0.2 animations:^{
    footer.frame = CGRectMake(0, CGRectGetHeight(self.view.frame) - CGRectGetHeight(footer.frame), CGRectGetWidth(footer.frame), CGRectGetHeight(footer.frame));
}];