FrameQueueWorker

private class FrameQueueWorker<T>{
  private List<T>       items;
  private Action<T,int> block;
  private int i, imax;

  public FrameQueueWorker(List<T> items, Action<T,int> block){
    this.items = items; this.block = block;
    i = 0; imax = items.Count;
  }

  public void Play(){
    if(i < imax) nextItem();
  }

  private void nextItem(){
    Utils.CoroutineStarter.Instance.Add(processNextItem());
  }

  private IEnumerator deferedNextItem(){
    yield return new WaitForEndOfFrame();
    nextItem();
  }

  private IEnumerator processNextItem(){
    yield return new WaitForEndOfFrame();
    block(items[i], i);
    i++;
    if(i < imax) Utils.CoroutineStarter.Instance.Add(deferedNextItem());
  }
}