Lenovo has been one of the slower companies when it comes to updating its products to Android 6.0 Marshmallow, but the Chinese smartphone maker isn't stopping. Following the release of the update for the A7000, K3 Note, and Vibe P1 over the past few months, today Lenovo has started sending out the Marshmallow bits to the Vibe S1.
So far the update has been spotted in the United Arab Emirates and India, but it's sure to make it to other territories in due course. Your phone will pop up a notification once the new software is ready to download and install.
That said, you might want to make sure you're on Wi-Fi before grabbing the file, since it's about 1.6GB in size (as you can see from the screenshot to the left). Also, keep in mind that you need to back up the stuff you have on your microSD card if you have previously switched the default storage device. Do this in order to not lose any data.
As is always the case with these things, the update may take a long time and your handset can restart several times while it's applying the new release. Don't panic and let it do its thing, it will be done eventually and then you'll get to play with all the new features that Google packed into Marshmallow - things such as Doze Mode and App Standby for improved battery life, the new permissions system, Now On Tap, and much more.