FPS.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class FPS : MonoBehaviour {

	Text text;
	float smootheddt = 1 / 60;
	float smoothvel;
	List<float> last100;

	// Use this for initialization
	void Start () {
		text = GetComponent<Text>();
		last100 = new List<float>();
	}
	
	// Update is called once per frame
	void Update () {
		smootheddt = Mathf.SmoothDamp(smootheddt, Time.deltaTime, ref smoothvel, 1);
		float fps = 1 / Time.deltaTime;
		float sfps = 1 / smootheddt;
		last100.Add(fps);
		while (last100.Count>100) last100.RemoveAt(0);
		float worst = last100[0];
		for (int i = 1; i < last100.Count; i++){
			worst = Mathf.Min(last100[i], worst);
		}
		text.text = "current:\t\t" + Mathf.Floor(fps * 100) / 100 +
					"\naverage:\t" + Mathf.Floor(sfps * 100) / 100 +
					"\nworst:\t\t" + Mathf.Floor(worst * 100) / 100;
	}
}

Rotate.cs

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

public class Rotate : MonoBehaviour {

	// Use this for initialization
	void Start () {
		
	}
	
	// Update is called once per frame
	void Update () {
		transform.localRotation =
			Quaternion.AngleAxis(90 * Time.deltaTime, Vector3.up) * transform.localRotation;
	}
}