Apps Might need some help with UI's..

[KevinStart]

So this is what I got..

I have been experimenting today with different layouts and I finally got what I wanted, but when I was testing it on other devices with other screen dimensions it really turned out bad.

Is there anything what you can do to prevent this?

My XML code:

 <?xml version="1.0" encoding="utf-8"?>

<RelativeLayout
        android:id="@+id/main_container"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android"
        android:background="@drawable/blurred_bj"
        android:orientation="vertical">
    <LinearLayout
            android:orientation="vertical"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/logo_container"
            android:layout_centerInParent="true"
            android:layout_above="@+id/button">
        <ImageView
                android:layout_marginBottom="85dp"
                android:id="@+id/logo"
                android:scaleType="centerInside"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/log"
                android:contentDescription="TODO"
                />
    </LinearLayout>

    <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/sign_in"
            android:id="@+id/sign_in"
            android:layout_marginBottom="45dp"
            android:layout_above="@+id/footer"
            android:layout_centerHorizontal="true"/>
    <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/sign_up"
            android:id="@+id/button"
            android:layout_above="@+id/sign_in"
            android:layout_centerHorizontal="true"/>

    <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            android:id="@+id/footer">
        <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/news"
                android:id="@+id/news" />
    </LinearLayout>
</RelativeLayout>