Samsung Galaxy S6 phones under Sprint have already been updated to the official Android 6.0.1 Marshmallow over-the-air (OTA) since last March 10. Sprint is the first carrier to release the upgrade to the device. 

Sprint has been leading software updates to devices with official Android 6.0.1 Marshmallow, including the Samsung Galaxy S6 phones. Other big carriers in the U.S. are expected to follow, but the question now is when and which network will take the next steps after Sprint?

T-Mobile has been on with its Marshmallow tracker since October 2015 when the software launched. However, Samsung Galaxy S6 of the carrier is still in the manufacturer development stage until now, since it was revealed for update to Android 6.0. Among T-Mobile's priority devices that have already been updated are HTC One M9 and LG G4. Only HTC One M8 is in the testing stage, while the rest remains to be in the development stage.

Meanwhile, AT&T, Verizon Wireless and US Cellular have not spoken about the update yet. Verizon had already released Marshmallow to Galaxy Note 5, while plans for Galaxy S6 still unknown as of now.

Android 6.0.1 Marshmallow update on Sprint for Samsung Galaxy S6 weighs 1.2 GB, heavier than expected since it brings a ton of features and enhancements.

The first ever Marshmallow update primarily brings major tweaks on the overall system performance, improved visibility of notification panel icons, more quick settings toggles for Private Mode in the status bar, minor tweaks on how the phone vibrates when locked with a fingerprint, like how the phone will only vibrate when the fingerprint is not recognized.

Marshmallow will also bring Doze, redesigned app drawer, Google Now on Tap, simpler volume controls, fingerprint and USB Type-C support, better app permissions and so many others.