One simple and extremely helpful improvement introduced in iOS 8 SDK is the auto-sizing of UITableViewCells. Prior to iOS 8, if you had a UITableView that has cells with varying heights, you'd have to implement UITableViewDelegate's -tableView:heightForRowAtIndexPath: and return a height based on -systemLayoutSizeFittingSize:, potentially caching the heights yourself.

In iOS 8, this becomes much easier if you do the following:

1. Use Auto Layout for your UITableViewCell (subclass).
2. Set UITableView.rowHeight = UITableViewAutomaticDimension
3. Set UITableView.estimatedRowHeight or implement -tableView:estimatedHeightForRowAtIndexPath:

You don't (and shouldn't) implement -tableView:heightForRowAtIndexPath: anymore!