OnePlus One gets Microsoft Cortana via Cyanogen OS 12.1.1 update [How to install]
OnePlus One gets Microsoft Cortana via Cyanogen OS 12.1.1 update [How to install]Cyanogen via Twitter (screen-shot)

OnePlus has announced that Android 6.0.1 Marshmallow-based CyanogenOS 13 OTA (over-the-air) update has finally been rolled out to OnePlus One. The company failed to keep its promise of releasing the firmware to the 2014 flagship device by the end of March, but users of the handset will be pleased that the delay was only for about a week.

"Our friends over at Cyanogen have informed us that CM 13.0 (ZNH0EAS26M) based on Marshmallow will drop starting tomorrow," wrote administrator of OnePlus forum (via GSM Arena) Friday. "The rollout will be staged so only some of you (random) will get it at first, and as always, patience is appreciated."

The Android 6.0.1 Marshmallow update comes a few days after OnePlus co-founder Carl Pei announced on his Twitter page that testing of the operating system for OnePlus One has entered the final stage. He said the firmware would roll out soon, but didn't reveal the date.

It may be mentioned that the Chinese smartphone maker released Android M-based OxygenOS v3.0 beta to select OnePlus 2 users, and the roll out is expected to happen soon based on the feedback of those who participate in the beta test.