real Layout is changed while running the App

I am making a game and i prepared a layout for my game but the layout gets changed after i run the app.It has also happened me before but i could find a way out of it.Let me know if you have any solution.I have also attached the pictures of my layout.

And also i wanna know how to prepare a responsive layout that runs and looks perfect on all android devices.

This is the Layout that i have prepared

This is what my layout becomes when i run the application

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Start!"
    android:id="@+id/button"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:onClick="start"
    android:visibility="visible"/>



<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:id="@+id/gameTimer"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:textSize="40sp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="0/0"
    android:id="@+id/gameScore"
    android:textSize="40sp"
    android:layout_alignParentTop="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:visibility="invisible"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="5+0"
    android:id="@+id/gameSum"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:textSize="35sp"
    android:visibility="invisible"/>

<GridLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/gameTimer"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="25dp"
    android:id="@+id/gridLayout"
    android:visibility="invisible">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="3"
        android:id="@+id/button0"
        android:layout_row="0"
        android:layout_gravity="fill"
        android:tag="0"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:layout_column="0"
        android:padding="30dp"
        android:textSize="40sp"
        android:onClick="selectAnswer"
        />


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="3"
        android:onClick="selectAnswer"
        android:id="@+id/button1"
        android:layout_row="1"
        android:layout_gravity="fill"
        android:tag="1"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:padding="30dp"
        android:textSize="40sp"
        android:layout_column="0"/>


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="selectAnswer"
        android:text="3"
        android:id="@+id/button2"
        android:layout_row="0"
        android:layout_gravity="fill"
        android:tag="2"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:padding="30dp"
        android:textSize="40sp"
        android:layout_column="1"/>


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="5"
        android:id="@+id/button3"
        android:layout_row="1"
        android:layout_gravity="fill"
        android:onClick="selectAnswer"
        android:tag="3"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:padding="30dp"
        android:textSize="40sp"
        android:layout_column="1"/>



</GridLayout>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:id="@+id/answerStatus"
    android:layout_below="@+id/gridLayout"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="30dp"
    android:textSize="40sp"/>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="PlayAgain!"
    android:id="@+id/again"
    android:layout_below="@+id/answerStatus"
    android:layout_centerHorizontal="true"
    android:onClick="reset"
    android:visibility="invisible"/>