Of course the primary reason for purchasing an Aquarius E4.5 is not the hardware (an Android version can already be purchased), it's for the Ubantu OS, which is pretty sweet. Canonical have worked hard to create a really clean and intuitive UX called Scopes, which puts icons out of sight until needed. The user swipes either from the top or side to reveal app icons, however they can also be gathered together on a single Scope card, if preferred.
Although very different in appearance to Android and iOS, Scopes isn't entirely unique as more than a few design cues have almost certainly been taken from, or at least inspired by, the likes of Palm, BlackBerry, and Jolla’s Sailfish.
If you're the kind of person who likes novelty and you don't care about the fact that a phone, such as this will lack support from app developers, we recommend that you check out Jolla smartphone or maybe take a look at the Puzzlephone.