<s>
Clef	B-Application
was	O
a	O
San	O
Francisco-based	O
technology	O
company	O
,	O
known	O
for	O
developing	O
a	O
mobile	B-Application
app	I-Application
that	O
created	O
a	O
two-factor	O
authentication	O
for	O
websites	O
.	O
</s>
<s>
Clef	B-Application
was	O
founded	O
in	O
2013	O
by	O
Mark	O
Hudnall	O
,	O
B	O
.	O
Byrne	O
and	O
Jesse	O
Pollak	O
.	O
</s>
<s>
Clef	B-Application
integrated	O
with	O
many	O
websites	O
and	O
applications	B-Application
,	O
including	O
WordPress	B-Application
.	O
</s>
<s>
On	O
March	O
17	O
,	O
2017	O
,	O
Clef	B-Application
announced	O
they	O
would	O
no	O
longer	O
support	O
the	O
plugin	O
after	O
June	O
6	O
,	O
2017	O
;	O
Clef	B-Application
was	O
acquired	O
by	O
Authy	O
,	O
another	O
2FA	O
service	O
,	O
which	O
later	O
got	O
acquired	O
by	O
Twilio	B-General_Concept
.	O
</s>
