In unity3D, Click = Touch?

The short answer is no, there is a unity remote android app (remote app) for simulating touching in editor mode. I think this maybe helpful.

The old android app was deprecated. go to related document for further information, and it now supports iOS and tvOS as well.

Short answer: yes, touch may be handled with Input.GetMouseButtonDown().

• Input.GetMouseButtonDown(), Input.mousePosition, and associated functions work as tap on the touch screen (which is kind of odd, but welcome). If you don't have a multi-touch game, this is a good way to keep the in-editor game functioning well while still keeping touch input for devices. ^{(source: Unity Community)}

• Mouse simulation with touches can be enabled/disabled with Input.simulateMouseWithTouches option. By default, this option is enabled.

• Though it is good for testing, I believe Input.GetTouch() should be used in production code (because it is able to handle simultaneous touches).

• Interesting approach is to add touch handling to OnMouseUp()/OnMouseDown() event:

    //  OnTouchDown.cs
    //  Allows "OnMouseDown()" events to work on the iPhone.
    //  Attach to the main camera.
  
    using UnityEngine;
    using System.Collections;
    using System.Collections.Generic;
  
    public class OnTouchDown : MonoBehaviour {
        void Update () {
            // Code for OnMouseDown in the iPhone. Unquote to test.
            RaycastHit hit = new RaycastHit();
            for (int i = 0; i < Input.touchCount; ++i)
                if (Input.GetTouch(i).phase.Equals(TouchPhase.Began)) {
                    // Construct a ray from the current touch coordinates
                    Ray ray = Camera.main.ScreenPointToRay(Input.GetTouch(i).position);
                    if (Physics.Raycast(ray, out hit))
                        hit.transform.gameObject.SendMessage("OnMouseDown");
                }
        }
    }
  

  ^{(source: Unity Answers)}

UPD.: There is Unity Remote mobile app for simulating touching in editor mode (works with Unity Editor 4 and Unity Editor 5).

From what I understand the Unity player does not allow you to trigger touch events, only mouse events.

But you can simulate fake touch events based on the mouse events, as explained in this blog post: http://2sa-studio.blogspot.com/2015/01/simulating-touch-events-from-mouse.html

void Update () {
    // Handle native touch events
    foreach (Touch touch in Input.touches) {
        HandleTouch(touch.fingerId, Camera.main.ScreenToWorldPoint(touch.position), touch.phase);
    }

    // Simulate touch events from mouse events
    if (Input.touchCount == 0) {
        if (Input.GetMouseButtonDown(0) ) {
            HandleTouch(10, Camera.main.ScreenToWorldPoint(Input.mousePosition), TouchPhase.Began);
        }
        if (Input.GetMouseButton(0) ) {
            HandleTouch(10, Camera.main.ScreenToWorldPoint(Input.mousePosition), TouchPhase.Moved);
        }
        if (Input.GetMouseButtonUp(0) ) {
            HandleTouch(10, Camera.main.ScreenToWorldPoint(Input.mousePosition), TouchPhase.Ended);
        }
    }
}

private void HandleTouch(int touchFingerId, Vector3 touchPosition, TouchPhase touchPhase) {
    switch (touchPhase) {
    case TouchPhase.Began:
        // TODO
        break;
    case TouchPhase.Moved:
        // TODO
        break;
    case TouchPhase.Ended:
        // TODO
        break;
    }
}