One small feature that somehow got left out from the above two links is that there is a new UI component offered in ADF Mobile now - Star Rating.
The official tag name is dvtm:ratingGauge - and you can find it in the DVT Mobile AMX component palette under the Gauge section.
You can configure how many stars you want to show for your rating in the data section of the property inspector, and you can even specify to advance in half steps.
The component supports multiple shapes that you can choose from - star, diamond, circle, rectangle
You can also specify a different shape to be displayed for the unselected spots.
The code for the above 3 components is:
<dvtm:ratingGauge id="ratingGauge1" value="2.5" maxValue="3" shape="circle"/>
<dvtm:ratingGauge id="ratingGauge2" unselectedShape="dot" inputIncrement="half"/>
<dvtm:ratingGauge id="ratingGauge3" shape="diamond"/>