Android: Screen Layout looks different on 2 phones of the same model

Question

I'm alpha testing an app and so for the first time people are looking at it on multiple devices. One person told me that buttons on his screen were getting cut off.

The weird thing is - we're using the same device. We're both using a Samsung Galaxy S3, so our screen resolutions should be the same.

1. Is there some setting on his (or my) phone where he might have changed the resolution to see things larger? (like ctrl + in a browser)
2. What else could cause this??

Screenshots and XML included below. Differences on Right: text is bigger, homemade ellipses is missing, Settings button is cut off

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.farmsoft.lunchguru.app.Pick_Restaurant"
    android:layout_height="match_parent"
    android:layout_width="match_parent">
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/PickRest_Header"
        android:textStyle="bold"
        android:textSize="20sp"
        android:gravity="center_horizontal"
        android:id="@+id/Lbl_Title"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/PickRest_CompanionHdr"/>

    <TableLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/Companion_Box">

    </TableLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="right"
        android:orientation="horizontal">

        <Button
            android:layout_width="45dp"
            android:layout_height="30dp"
            android:text="•••"
            android:gravity="top"
            android:id="@+id/More_Companions"
            android:onClick="onClick_More_Companions"/>

        </LinearLayout>

    <Space
        android:layout_width="0dip"
        android:layout_height="35dp" />

    <com.farmsoft.lunchguru.utils.ListButton
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/PickRest_Recommend_Button"
        android:id="@+id/Recommend_Button"
        android:onClick="onClick_Recommend"
        android:enabled="false"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/OR"
        android:gravity="center_horizontal"
        android:textSize="10pt"
        android:textStyle="bold"/>

    <com.farmsoft.lunchguru.utils.ListButton
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/PickRest_Nearby_Button"
        android:id="@+id/Nearby_Button"
        android:onClick="onClick_Nearby"
        android:enabled="false"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/OR"
        android:gravity="center_horizontal"
        android:textSize="10pt"
        android:textStyle="bold"/>

    <com.farmsoft.lunchguru.utils.ListButton
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/PickRest_Search_Button"
        android:id="@+id/Search_Button"
        android:onClick="onClick_Search"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/Lbl_Version"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/Lbl_Coordinates"
        android:text="@string/PickRest_Coordinates_Load"/>

    <Space
        android:layout_width="0dip"
        android:layout_height="35dp" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/PickRest_IAteThere_Button"
        android:id="@+id/Attend_Button"
        android:onClick="onClick_Attend"
        android:visibility="gone"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/Ratings_Button"
            android:text="@string/PickRest_Rating_Button"
            android:onClick="onClick_Ratings"
            android:enabled="false"/>
        <Space
            android:layout_width="0dp"
            android:layout_height="0dip"
            android:layout_weight="1" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/Settings_Button"
            android:text="@string/PickRest_Settings_Button"
            android:onClick="onClick_Settings"/>
        </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/Connections_Button"
            android:text="@string/PickRest_Connections_Button"
            android:onClick="onClick_Connections"/>

        <Space
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"/>
        </LinearLayout>
</LinearLayout>
</ScrollView>

Answer 1

You're doing everything correctly, by using sp to specify font size. This will scale the fonts you've chosen based on the system-wide font-scale. One of the users has increased the system-wide font-size. On AOSP phones, this is in Settings/Display/Font Size. Should be in a similar spot for Samsung devices.