Update schedule of Android

Google provides major updates, incremental
in nature, to Android every six to nine
months, which most devices are capable of
receiving over the air. [76] The latest major
update is Android 4.4 KitKat.[5]
Compared to its chief rival mobile operating
system, namely iOS, Android updates are
typically slow to reach actual devices. For
devices not under the Nexus brand, updates
often arrive months from the time the given
version is officially released. [77] This is
caused partly due to the extensive variation
in hardware of Android devices, to which
each update must be specifically tailored, as
the official Google source code only runs on
their flagship Nexus devices. Porting Android
to specific hardware is a time- and resource-
consuming process for device manufacturers,
who prioritize their newest devices and often
leave older ones behind.[77] Hence, older
smartphones are frequently not updated if
the manufacturer decides it is not worth their
time, regardless of whether the phone is
capable of running the update. This problem
is compounded when manufacturers
customize Android with their own interface
and apps, which must be reapplied to each
new release. Additional delays can be
introduced by wireless carriers who, after
receiving updates from manufacturers,
further customize and brand Android to their
needs and conduct extensive testing on their
networks before sending the update out to
users. [77]
The lack of after-sale support from
manufacturers and carriers has been widely
criticized by consumer groups and the
technology media. [78][79] Some
commentators have noted that the industry
has a financial incentive not to update their
devices, as the lack of updates for existing
devices fuels the purchase of newer ones, [80]
an attitude described as "insulting". [79] The
Guardian has complained that the
complicated method of distribution for
updates is only complicated because
manufacturers and carriers have designed it
that way. [79]
In 2011, Google partnered with a number of
industry players to announce an "Android
Update Alliance", pledging to deliver timely
updates for every device for 18 months after
its release; [81] however, this alliance has
never been mentioned since. [77] Google then
began updating many of its services,
including Google Maps and Google Play Music ,
as applications independent from Android
itself, and also introduced a system-level
component providing APIs for Google services
— installed automatically and updated
directly by Google, and supportive of nearly
all devices running Android version 2.2 and
higher — through Google Play Services