The Meizu MX4 comes with the custom-made Flyme OS, now in its 4.0 installment, based on Android KitKat 4.4.2 (Meizu is currently working on a 5.0 Lollipop update). It takes after its Chinese siblings from MiUI and others and has a one-level interface with only homescreen and no app drawer, similarly to Apple's iOS.
Here's a quick look at Flyme OS 4.0 on the Meizu MX4.
The lockscreen on the Meizu MX4 is a pretty simple affair. You drag upwards to unlock and have the option of passcode-locking or pattern it. There are no shortcuts on the lockscreen and you can get into the homescreen or camera with a simple swipe on the screen even when its off.
A swipe to the right brings up the settings menu, a left one will unlock you into the camera, a swipe down will prompt up the notification area and a swipe upward unlock the phone into the homescreen.
The latter is simpler still. You get two but you can add more later on. The homescreen gathers all of your app icons and you can add widgets into the mix. Widgets can go on each homescreen, instead of having their separate one like on the MX3.
Aside from adding widgets you can also align apps to the top or the bottom of the screen - a step up from the iOS homescreen, which has a mind of its own in this regard.
The notification area pulls down the whole way and not just for a single roll like before. You get a set of five circular toggles for various settings and you can expand them with a swipe down or with the dedicated virtual button in the top right.
The rest of the notification area is a basic list or expandable, actionable notifications.
Switching between tasks is done with a pull up menu from the bottom of the screen. It looks like iOS 6 in a way but works differently - you have to swipe apps up or down to dismiss them.
The settings menu on the Meizu MX4 is laid out in a tabbed interface, with the main categories on the left and the related options on the right. In the default view, the settings categories are just icons but a swipe will reveal their full names if you can't find what you're looking for.
You can choose a different theme for the Meizu MX4. There are some preloaded but you can browse the App Center for more - some of them are paid but there are many free and a lot to choose from. There's also a variety of built in wallpapers.
Flyme OS can be tough to get around at first but once you've gotten your bearings it becomes a treat to work with. Meizu is keeping things as simple as possible and everything works seamlessly without any hiccups.
The resemblance to Apple's iOS is hard to ignore but that's true of most custom launchers that come out of China these days. That doesn't make Flyme OS bad though.