The State of Pie

If you haven't realized yet, Google isn't really a phone manufacturer. It is first and foremost, a software company. That's why you see their Android mobile OS on handsets other than their very own smartphones. They're mainly making the Pixel phones to showcase how they envision their OS in its purest form. That's because manufacturers put their own taste on it. Some non-Google sanctioned features are great, but all of these come at an extra heft on the resources.
An advantage of the Pixel and Android One phones is that they get their updates straight from Google. For phones like Samsung's Note and S lines that have their own skin on top of Android, further polish needs to be done. It's not a surprise, then, that the latest version of Android can only be found in either Pixel or Android One phones. LG’s G7 One is the latest one to get it according to some websites.
So, before Android 9 dubbed as Android Pie goes mainstream, I decided to give you my favourite new features.

Navigation

The very first thing you see when you unlock your phone is the home screen. From there, we generally use intuition to get around. In the beginning, that involved using a blatantly graphical interface. A picture of a home, for example, was used to connote the home button.
As smartphone design continues to develop, the interface becomes more and more efficient. Android 9 Pie shows this by doing away with the navigation buttons altogether. What Google put in its place are gesture controls. It looks cleaner because some elements that took up precious screen real estate are now gone. The new gesture-based interface should be more efficient as well. Using a single gesture to get to a specific menu item should be quicker as compared to a couple of taps. A simple swipe to the right, for example, would instantly bring you to your most recently used app. On Android Oreo, you had to tap on the "recents" button and then swipe down to rifle through your apps. If you multitask heavily on your device, this is a potential time-saving feature.
While gesture control is new to Android this year, it has been implemented in Apple's iPhone X last year. So, a little imitation and polishing by Google come into play here. The multitasking gesture, for example, is a bit similar to how iOS implemented it on their own phones except for some subtle differences.

App Actions and Slices

Speaking of hastening the interface, the new A.I.-based app suggestions work to achieve that as well. They're called the App Actions and Slices.
Through machine learning, Android Pie predicts your actions based on the time of day. App Action suggests frequently executed functions and makes a shortcut for that action right on the app launcher screen. When you're about to clock out from work, for example, an App Action to call an Uber ride home pops up right on the launcher.
Slices is another great tool that aims to hasten our interactions with our phone. Similar to App Actions, it also suggests frequently executed actions. This time, it does its business on the search bar. For, instance, if you search for a restaurant name, it will also show the Food Panda and Deliveroo shortcuts if you have those apps installed.
Since both of these features are based on machine learning, the more often you use them, the better they get. Over time, that means it gets better in both app suggestion, timing, and context.

Digital Well Being

You may already see a pattern here. Google is making its interface easier to navigate. This tends to make you spend less time looking for stuff on your phone. This way, we spend more time looking at actual information. The OS truly makes information easier and quicker to access. Whether that translates to us spending less time on our phones or the opposite another conversation.
To this end, Google introduces Digital Well Being. It's a suite of features that aim to make us spend less time with our highly addictive smartphones. It's a combination of old but improved features and completely new ones.
The "do not disturb" function, for example, no longer just dims audio distractions. It also turns off visual distractions such a notification LED when it's turned on.
The most interesting feature of the Digital Well Being suite has got to be its usage tracking. Sure, we get how much data each app is consuming or how much time we spend on an app is already stored on Oreo. But, Google gathers more relative data. From the app, we also get to know how much notification we get from each app and how often we pick up our phones.
Furthermore, it also allows us to set a timer that would limit our usage of certain apps. If, for example, we exceed today's Facebook usage allowance, we lose access to the app for the rest of the day.

When Will We Be Getting Our Slice of Pie?

Pixels and some Android One handsets already have the Android Pie update. So, when will others have it too?
Currently, the updates are limited until Android One phones. But, the bigger manufacturers such as Samsung and Huawei already have beta programs for their flagships.
Whatever the case, it's expected to be a slow roll-out. There are some enhancements on this update that just aren't compatible with a lot of the hardware in circulation. Questions pertaining to what to do with home-buttons, for example, arises with the gesture control in mind.
Historically, this has been the case as well. Android Oreo isn't even on 25% of active devices right now. In the non-flagship department, it's even lower because some of them don't even get updates this big.
So, if you're not using an Android One or a flagship smartphone, you can expect your update in the next few years if it'll come at all. But, being an open source OS, there are a lot of developers out there that can easily flash the latest OS on your phone if you're willing to risk it.