Here’s a control called DPMeterView from Pierre Dulac that you can use to create custom gauges with any image. The control provides methods so that the gauge can easily be used as progress indicators or rating indicators. The gauges are animated, and there’s even a way to set up gravity for the gauges so the indicated fill adjusts for the tilt of the phone.
There are a number of examples providing included a star rating indicator. You can follow the included examples and create your own custom indicators using core graphics.
Here’s an image from the readme showing the included example indicators with gravity on a tilted device:
You can find DPMeterView on Github here.
A great control for creating custom gauges.