OnePlus One gets update via custom ROM by Dirty Unicorns. This new custom ROM is based on Android 5.1.1 Lollipop operating system.

OnePlus One In Pictures

The Android 5.1.1 Lollipop custom built ROM v9.3 is only for OnePlus One (aka bacon). The ROM v9.3 brings tons of bug-fixes and feature enhancements including the amazing Material Design UI. Few main features are listed below.

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Key Features of Custom ROM

Update to Android 5.1.1
Materialize DSP manager
Fix system UI
Remove voice dialer
Fix for navigation bar
Fix for playing video and audio
List view animation
Fix various theme issues
Add back notification LED settings
Fix battery and notification lights.

Points to Remember Before Installing.

• The smartphone should be rooted with the latest ClockworkMod (CWM) or TWRP recovery tool before installing the custom ROM and its bootloader is unlocked.
• Backup all the important data and additional files. Installing custom ROM on the OnePlus One will wipe all the data.
• Use CWM or TWRP recovery tool to create a complete image of the existing phone setup. To create backup in recovery tool, choose Backup and Restore and tap Backup.
• Ensure the smartphone have at-least 80 percent of battery charge to avoid power off during installation process.
• Make sure USB drivers of OnePlus One have been installed on the PC.
• This installation guide is only for installing the Dirty Unicorns custom ROM v9.3 for European variant OnePlus One (aka bacon). Installing this custom ROM on any other devices including other variant of OnePlus One might brick the device.

Before starting the installation process, download required files. Links provided below.

Android 5.1.1 Lollipop custom ROM v9.7 by Dirty Unicorns for OnePlus One

Google Apps

Complete Step-by-step Installation Guide For Android 5.1.1 Lollipop for OnePlus One using Dirty Unicorns Custom ROM v9.3

Step 1: Connect OnePlus One to the computer using USB cable and turn on the Phone's USB mass storage.

Step 2: Copy the downloaded zip files (Dirty Unicorns v9.3 ROM.zip and Gapps.zip) to the phone's SD card root.

Step 3: Turn off the smartphone and disconnect from the PC.

Step 4: Boot the smartphone to Recovery Mode, by pressing and holding Volume Up + Home + Power buttons together.

Step 5: Perform full data wipe by selecting 'wipe data/factory reset' option in the recovery mode. Use Volume keys to navigate and Power button to select, while operating in the recovery mode.
Step 6: Clear cache memory of the OnePlus One by selecting 'wipe cache partition'

Step 7: Go back to recovery mode and select 'advance' and choose 'wipe dalvik cache' to perform complete wipe.

Step 8: Return to the main menu of the recovery mode and select 'install zip from SD card'. Navigate to the phone's SD card and select the zip file (Dirty Unicorns v9.3 ROM.zip) which copied earlier to the root folder of phone's SD card.

Step 9: Repeat step 8 to install Gapps.zip (Google Apps).

Step 10: Once the custom ROM and Google Apps installation completes, go back to main menu of recovery mode and reboot the device by selecting 'reboot system now'.

Now the smartphone will take about 5 minutes to boot for the first time. Wait till the device starts. Now the OnePlus One must be running the Android 5.1.1 Lollipop custom ROM by Dirty Unicorns v9.3.

[Note: This procedure is highly technical. If the smartphone brick or damaged during the installation process, GizBot cannot be held responsible for any kind of damage for the smartphone. Hence, the user has to perform the installation on their own risk.]

Source: XDA

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