How to create a custom progress bar

First you need to create a progress bar layout file. Let's call it my_custom_pb.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<item android:id="@android:id/background" android:drawable="@drawable/mybg"/>

<item android:id="@android:id/secondaryProgress">

<clip>

<shape>

<corners android:radius="5dip" />

<gradient

android:startColor="#80d3ff00"

android:centerColor="#80b6ff00"

android:centerY="0.75"

android:endColor="#a0cbff00"

android:angle="270"

/>

</shape>
</clip>
</item>

<item android:id="@android:id/progress">

<clip android:drawable="@drawable/myprogress"/>

</item>
</layer-list>

Notice you can either use a simple 9 patch drawable or make your own custom shape!
Then you would add that custom progress bar to the layout you want that bar to appear:

<ProgressBar

android:id="@+id/mypb"

android:layout_width="120px"

android:layout_height="10px"

android:progressDrawable="@drawable/my_custom_pb"

android:max="5"

android:progress="1" />

And finally you would access it from your code like you would with any regular progress bar:

myProgress = (ProgressBar)findViewById(R.id.mypb);

myProgress.setProgress((int)value);

--
Special Thx to Mikael for this one.