1. Double tap on home screen to lock phone
2. Option to scale down icons size.
3. In addition to pop up view, drag and drop an app directly from the apps edge panel to open in split screen view.
4.Smoother animation with no stutters.
5. More edge lighting effects and clock styles
6. Better battery optimisation.
7. Wallpaper motion effect.
8. Option to bring the search bar in app drawer at the bottom.
all are present if you use goodlock apk and 1st option is there in one handed operation + or soft edge panal option .... and unfortunately android 3.0 is os by Google who already settled the features of their own
yes it's not double tab but easier than that also it's sipmly swipe .. or soft key edge single tap or accessibility settings assistant menu single tap.....double or single tap option samsung preserved for AOD