Sharp wants to be playing with the big boys like HTC and Samsung when it comes to Android phones and it's doing so by releasing its own custom UI, called Feel UX. Now there is a lot of hate against custom Android skins which manufacturers apply to their devices, and that's completely understandable - because most of them are truly shit.
Sharp's own version seems to look a lot different though but doesn't do away with the stock feeling of ICS completely. What looks amazing is the lockscreen, it's a lot better than what anyone else out there has at the moment. It's a lot more interactive then your average lockscreen. What I didn't like were the ugly base layers under the icons in the app menu, it looks really tacky.