Move object to grid

I recognized your example. It's mobile game called 1010! You can implement it in Unity very easily. Here are a few tips:

1. Create one white image (You will change color of this sprite by Color value in Sprite renderer) and use it as 2D Sprite prefab.

2. Create class OneItem with public variable Vector2 position;

3. In Start() method Instantiate your prefab 100 times and setup position according to example

4. For grad and drop use something like this:

 bool dragging = false;
 Vector2 dragEndPosition;
 void OnMouseDown()
 {
     dragging = true;
 }    
 void OnMouseUp()
 {
     if (dragging) {
         //TODO: here use dragEndPosition to change values in net 
     }
     dragging = false;
 }
 void Update()
 {
     if (dragging)
     {
         RaycastHit2D hit = Physics2D.Raycast(Camera.main.ScreenToWorldPoint(Input.mousePosition), Vector2.zero);
         if(hit.collider != null)
         {
             dragEndPosition = hit.collider.gameObject.getComponent<OneItem>().position;
         }
     }
 }

1. Use your imagination and create whatever features you want.