AndroidJSCore is a great one. And here is another little library I wrote for evaluating JavaScript:
https://github.com/evgenyneu/js-evaluator-for-android
jsEvaluator.evaluate("function hello(){ return 'Hello world!'; } hello();", new JsCallback() {
@Override
public void onResult(final String result) {
// get result here (optional)
}
});
It creates a WebView behind the scenes. Works on Android version 3 and newer.