I just started using iPlotz and it is very nice but I find many things missing for the iPhone and Android. (e.g. star rating element)
It would be nice if we could contribute our own elements (not snippets but actual elements with properties and all)
The star rating icons can be found in the icon list. Place a icon placeholder on the stage and double-click to get the list of icons. You can also upload your own image. Please change to the My Images tab to upload images.