Using Jo and PhoneGap, you can create native iPhone/Android/Symbian applications which are both lightweight and responsive as well as pretty. Jo currently supports the follow platforms – webOS, iOS, Android, Symbian, Safari and Chrome.
Sencha Animator comes as a desktop application used to create rich HTML5 animation. It’s currently in its infancy but could have real potential. There is one drawback at this point-in-time however; it requires a Webkit browser to work. This means it will work in Google Chrome, Apple Safari, Iphone, Ipad, Blackberry torch, Google Android and other Webkit based browsers. But it will not fully work in IE, Opera or Firefox. At least not until the CSS3 is fully supported (IE 9 claims support).