FootPrints.cs

using UnityEngine;
using System.Collections;

public class FootPrints : MonoBehaviour {

    private GameObject text;
    public GameObject Camera;

    void Start()
    {
        text = transform.Find ("PleaseStandHere").gameObject;
    }

    // Update is called once per frame
    void Update () {
        if (text != null) {
            if (Time.frameCount > 5 && Time.time > 2) {
                if ((text.transform.position - Camera.transform.position).magnitude < 0.35f) {
                    GameObject.Destroy (text);
                    text = null;
                    Platform.instance.activateUIMesh ();
                }
            }
        }
    }
}