Help making a "launcher screen" for my app, and making it look right across devices
<p>I posted a question here before: <a href="http://stackoverflow.com/questions/6539578/good-way-to-make-a-launcher-screen-for-sub-apps-within-your-app">Good way to make a launcher screen for sub-apps within your app?</a>, and then started working on other parts of the app, and now I'm back to the same thing. </p>

<p>I want to make a nice screen with icons that the user can press, with room for more icons at a later date. Or maybe something different, I'm not sure. </p>

<p>Here's a current screenshot of what it looks like:<img src="http://i.stack.imgur.com/Ph0dn.png" alt="enter image description here"></p>

<p>It looks pretty bad there, on my phone it looks better, with less space between the apps (this is a friend's phone), but ideally I want it to look good on all devices. </p>

<p>My XML code for this is as follows: </p>

<pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
    &lt;GridView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/gridview"
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent"
        android:numColumns="auto_fit"
        android:verticalSpacing="10dp"
        android:horizontalSpacing="20dp"
        android:columnWidth="90dp"   
        android:stretchMode="columnWidth"
        android:gravity="center"
        android:background="#FF6699FF"
    /&gt;
</code></pre>

<p>Any tips/suggestions are appreciated, I want to make this look good.
I'm not sure what format to store the icons in, right now they're just large (400x400 or so) png files. </p>
