Grouped UITableView has 20px of extra padding at the bottom

You can use contentInset to compensate the 20px extra bottom margin:

tableView.contentInset = UIEdgeInsetsMake(0, 0, -20, 0);

@frankWhite' solution works great, but here is a better solution to avoid typing 0.1, 0.001 or others to make it less ambiguous.

// Swift version
func tableView(tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {

    // remove bottom extra 20px space.
    return CGFloat.min
}

// Objective-C version
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {

    // remove bottom extra 20px space.
    return CGFLOAT_MIN;
} 

-(CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {
   return 0.01;
} 

It's work for me

in Swift 3

override func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
    return CGFloat.leastNormalMagnitude
}