OnePlus had confirmed November 2015 that the flagship smartphone One will get Android Marshmallow by the end of March 2016.
Now, company co-founder Carl Pei has confirmed via Twitter that the OnePlus One Android Marshmallow OS testing has entered the final stage and would try to roll out the firmware soon.
However, Pei refrained from revealing the estimated time of arrival of the update to the public as the testing involves third party software developer (Cyanogen).
Even though OnePlus failed to keep the promise, the company has to be appreciated for taking responsibility for the delay and informing the public that it is taking steps to release the update as soon as possible.
In a related development, OnePlus released Android M-based OxygenOS v3.0 beta to select OnePlus 2 users. Based on the feedback, the company is expected to commence the update roll-out for the 2015 flagship by the end of April.
In addition to all the goodies of Android M, OnePlus 2 and its predecessor One will also get new custom camera UI, visually appealing wallpaper, app shelf UI, new setting options and more.