Thumbs up for Littera! I just tried it and it worked great!
I can no longer get the old Java Hiero to run. The URL it used to be hosted at is no longer valid. When I try to run it from the newer location, at n4te, my browser will not allow it to run, even when I try changing the Java security preferences.
I used the Littera browser app before I even noticed the Hiero DMG link.. Maybe the Hiero DMG works, but I think Littera has more features and options.