After breaking off with Cyanogen Inc a couple of months ago, OnePlus has decided to run the Oxygen OS in all regions, except on its home turf. In China, the One Plus 2 runs on Hydrogen OS, that comes in Chinese and is slightly different from the Oxygen OS. Meanwhile, the Oxygen OS 2.0 is a leaner, cleaner, and a more optimized version of the Android 5.0 Lollipop. Though it uses a custom skin, a lot of features of stock Android are offered as is, such as the app icons, layouts and notification drawers.
The changes are mostly visible in the hardware dependent options, such as the fingerprint reader and alert slider. The Oxygen OS has added several nifty improvements atop the vanilla Android code. Quick Settings lets you hide and re-arrange the icons as per your requirements by simply tapping on the “Edit” mode. ‘Double tap to wake up’ option exists alongside other custom gestures to launch predefined apps. For instance, when the phone is in sleep mode, drawing “o” on the screen opens the Camera app, whereas drawing “v” turns on the flashlight.

An audio tuner powered by MaxxAudio is quite handy as a software equaliser, with a lot of presets and slider options that are customizable to suit one’s preference. We do miss the AudioFX of Cyanogen OS on this device, but the Audio Tuner isn’t too bad either. The capacitive keys with blue backlight that are placed on either side of the Home button can be customized to perform predefined functions such as launching the Google Search Assistant, opening the camera app and opening the last used apps. A new feature dubbed Shelf is accessible from the home screen by simply swiping from the left to the right. The Shelf is basically a custom drawer that stores the frequently accessed apps and contact cards. Under these two folders, you can also add widgets, with the default one being Google Calendar.
A dark mode reverses the white background-bearing interface to a darker colour. In this theme, one can switch accent colours found on the toggle switches and other system interfaces, to any of the eight different colours. The LED notification colours can also be customized, irrespective of the dark mode. SwiftKey’s keyboard has been baked inside the OS, which means that it has been integrated to be a part of the system and is not a removable app. But, you can easily switch to default Google Keyboard or install another third party one. App permissions for third party apps have been added to basically control the way they behave or consume resources while running in the background.
We are certainly going to wait to see the App permission implementation from the Android 6.0 Marshmallow update, once it is made available by OnePlus. The Oxygen OS is one of the most slick and smooth custom skins coming with a useful bunch of additions in non-Nexus phones right now. The overall experience on the OnePlus 2 is lag-free and we thoroughly enjoyed the fresh take that it offered.