<s>
WatchKit	B-Device
is	O
a	O
framework	B-Architecture
provided	O
by	O
Apple	O
to	O
develop	O
interfaces	B-Application
for	O
Apple	B-Device
Watch	I-Device
applications	B-Application
.	O
</s>
<s>
To	O
develop	O
using	O
WatchKit	B-Device
,	O
Apple	O
provides	O
more	O
information	O
and	O
resources	O
in	O
the	O
WatchKit	B-Device
library	B-Library
.	O
</s>
<s>
WatchKit	B-Device
contains	O
all	O
the	O
classes	O
that	O
a	O
WatchKit	B-Device
extension	O
uses	O
to	O
develop	O
an	O
application	O
.	O
</s>
<s>
WatchKit	B-Device
provides	O
some	O
classes	O
for	O
general	O
purposes	O
,	O
as	O
representing	O
controllers	O
,	O
interfaces	B-Application
and	O
alert	O
actions	O
.	O
</s>
<s>
WatchKit	B-Device
provides	O
two	O
protocols	O
:	O
WKExtensionDelegate	O
and	O
WKImageAnimatable	O
.	O
</s>
<s>
WKExtensionDelegate	O
is	O
intended	O
to	O
manage	O
the	O
behaviour	O
of	O
the	O
WatchKit	B-Device
extension	O
and	O
WKImageAnimatable	O
controls	O
the	O
playback	O
of	O
animated	O
images	O
.	O
</s>
