- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGRect frame = self.floatingView.frame;
    frame.origin.y = scrollView.contentOffset.y;
    self.floatingView.frame = frame;

    [self.view bringSubviewToFront:self.floatingView];
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGRect frame = self.floatingView.frame;
    frame.origin.y = scrollView.contentOffset.y + self.tableView.frame.size.height - self.floatingView.frame.size.height;
    self.floatingView.frame = frame;

    [self.view bringSubviewToFront:self.floatingView];
}

[self.navigationController.view addSubview:yourView];

UIButton *goToTop = [UIButton buttonWithType:UIButtonTypeCustom];
goToTop.frame = CGRectMake(130, 70, 60, 20);
[goToTop setTitle:@"go to top" forState:UIControlStateNormal];
[goToTop addTarget:self action:@selector(goToTop) forControlEvents:UIControlEventTouchUpInside];
[goToTop setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[goToTop.layer setBorderColor:[[UIColor whiteColor] CGColor]];
goToTop.titleLabel.font = [UIFont fontWithName:@"Helvetica-Bold" size:13];
[self.navigationController.view addSubview:goToTop];

UIWindow *window = [[UIApplication sharedApplication] keyWindow];
UIButton *btn =[UIButton buttonWithType:UIButtonTypeCustom];
[btn setFrame:CGRectMake(60, 200,40, 60)];
[btn addTarget:self action:@selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];
[window addSubview:btn];