Simple Timer Event Dispatcher using delegate

TimerManager

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class TimerManager : MonoBehaviour {

	public delegate void Callback();
	
	static TimerManager _instance = null;
	
	public static TimerManager Instance {
		get {
			if(_instance == null) {
				GameObject go = new GameObject("TimerManager");
				_instance = go.AddComponent<TimerManager>();
			}
			return _instance;
		}
	}
	/// <summary>
	/// Internal Timer Object.
	/// </summary>
	class Timer{
		public string id;
		public float interval;
		public Callback callback;
		public int repeatCount;
		
		
		public Timer(string id, float interval, Callback callback, int repeatCount) {
			this.id = id; this.interval =interval; this.callback = callback; this.repeatCount =repeatCount;
		}
		/// <summary>
		/// The temp interval vary value.
		/// </summary>
		private float currInterval;
		
		/// <summary>
		/// Tick this instance.
		/// return true if this timer complete, otherwise return false
		/// </summary>
		public bool Tick() {
			float deltaTime = Time.deltaTime;
			
			currInterval += deltaTime;
			if(currInterval >= interval) {
				currInterval = 0;
				if(callback != null) 
					callback();
				
				if(repeatCount > 0) {
					repeatCount --;
					//if repeatCount equal 0, we need remove this timer
					if(repeatCount == 0) {
						return true;
					}
				}
			}
			return false;
		}
	}
	
	private List<Timer> timerList = new List<Timer>();
	
	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
		completeTimers.Clear();
		
		for(int i = 0; i < timerList.Count; ++i){
			if(timerList[i].Tick()) {
				timerList[i].RemoveAt(i);
				--i;
			}
		}
	}
	
	
	public void RegisterTimer(string id, float interval, Callback callback, int repeatCount = 0) {
		timerList.Add(new Timer(id, interval, callback, repeatCount));
	}
	
	public void UnregisterTimer(string id) {
		int index = -1;
		for(int i = 0 ; i < timerList.Count; i++) {
			if(	timerList[i].id == id) {
				index = i;	
			}
		}
		
		if(index != -1){
			timerList.RemoveAt(index);	
		}
	}
}