<s>
Upptalk	B-Protocol
(	O
formerly	O
known	O
as	O
Yuilop	B-Protocol
)	O
was	O
a	O
proprietary	B-Application
voice-over-IP	B-Application
service	O
and	O
software	B-Application
application	I-Application
that	O
provided	O
mobile	O
phone	O
numbers	O
in	O
the	O
cloud	O
and	O
allows	O
users	O
to	O
call	O
or	O
text	O
any	O
phone	O
for	O
free	O
whether	O
or	O
not	O
the	O
device	O
receiving	O
the	O
calls	O
and	O
texts	O
has	O
the	O
Yuilop	B-Protocol
application	O
.	O
</s>
<s>
Yuilop	B-Protocol
provided	O
phone	O
numbers	O
can	O
be	O
accessed	O
across	O
any	O
device	O
on	O
the	O
internet	O
(	O
IP	O
)	O
and	O
are	O
reachable	O
via	O
regular	O
phone	O
calls	O
(	O
PSTN	O
)	O
from	O
any	O
landline	B-Application
or	O
mobile	O
phone	O
,	O
and	O
SMS	B-Device
.	O
</s>
<s>
Calls	O
and	O
chats	O
to	O
other	O
users	O
within	O
the	O
yuilop	B-Protocol
network	O
service	O
are	O
free	O
of	O
charge	O
.	O
</s>
<s>
Unlike	O
most	O
other	O
VoIP	B-Application
services	O
,	O
yuilop	B-Protocol
does	O
not	O
charge	O
for	O
off	O
network	O
communication	O
.	O
</s>
<s>
Calls	O
and	O
SMS	B-Device
to	O
landline	B-Application
telephones	I-Application
and	O
mobile	O
phones	O
use	O
virtual	O
credits	O
that	O
are	O
earned	O
for	O
free	O
through	O
participating	O
in	O
promotional	O
activities	O
and	O
using	O
the	O
app	O
.	O
</s>
<s>
Yuilop	B-Protocol
does	O
not	O
require	O
credit	O
for	O
national	O
calls	O
and	O
SMS	B-Device
in	O
the	O
U.S.	O
Yuilop	B-Protocol
has	O
additional	O
features	O
,	O
including	O
instant	B-Application
messaging	I-Application
,	O
group	O
chat	O
,	O
and	O
location	O
,	O
and	O
photo	O
sharing	O
.	O
</s>
<s>
Competitors	O
include	O
Skype	B-Application
,	O
Viber	B-Application
and	O
Google	B-Application
Voice	I-Application
.	O
</s>
<s>
Yuilop	B-Protocol
was	O
created	O
by	O
former	O
simyo	O
CEO	O
,	O
Jochen	O
Doppelhammer	O
in	O
November	O
2010	O
.	O
</s>
<s>
Yuilop	B-Protocol
's	O
headquarters	O
are	O
located	O
in	O
Barcelona	O
,	O
Spain	O
and	O
the	O
app	O
is	O
available	O
in	O
over	O
200	O
countries	O
including	O
the	O
United	O
States	O
,	O
United	O
Kingdom	O
,	O
Germany	O
,	O
Italy	O
,	O
Spain	O
,	O
Israel	O
,	O
and	O
Mexico	O
.	O
</s>
<s>
The	O
app	O
had	O
approximately	O
5	O
million	O
users	O
and	O
is	O
available	O
on	O
Android	B-Application
,	O
iOS	B-Application
,	O
Windows	B-Protocol
Phone	I-Protocol
,	O
BlackBerry	B-Application
OS	I-Application
.	O
</s>
<s>
As	O
of	O
July	O
2013	O
,	O
Yuilop	B-Protocol
has	O
raised	O
approximately	O
$9	O
million	O
in	O
funding	O
from	O
investors	O
such	O
as	O
Nauta	O
Capital	O
,	O
Shortcut	O
Ventures	O
GmbH	O
,	O
Bright	O
Capital	O
,	O
and	O
the	O
Spanish	O
government	O
.	O
</s>
<s>
In	O
2014	O
,	O
the	O
company	O
UppTalk	B-Protocol
entered	O
insolvency	O
procedures	O
.	O
</s>
<s>
Yuilop	B-Protocol
's	O
services	O
are	O
split	O
into	O
two	O
main	O
categories	O
:	O
</s>
<s>
Calls	O
and	O
texts	O
made	O
to	O
other	O
Yuilop	B-Protocol
users	O
using	O
VoIP	B-Application
.	O
</s>
<s>
Calls	O
and	O
SMS	B-Device
made	O
to	O
mobile	O
phones	O
and	O
landlines	B-Application
and	O
virtual	O
numbers	O
like	O
Skype	B-Application
and	O
Google	B-Application
Voice	I-Application
by	O
connecting	O
to	O
the	O
Public	O
Switched	O
Telephone	O
Network	O
(	O
PSTN	O
)	O
.	O
</s>
<s>
Yuilop	B-Protocol
provides	O
free	O
calling	O
and	O
texting	O
between	O
Yuilop	B-Protocol
users	O
as	O
well	O
as	O
to	O
mobile	O
and	O
landline	B-Application
numbers	O
not	O
in	O
the	O
Yuilop	B-Protocol
network	O
.	O
</s>
<s>
Yuilop	B-Protocol
allows	O
these	O
registered	O
users	O
to	O
communicate	O
through	O
instant	B-Application
messaging	I-Application
,	O
SMS	B-Device
,	O
voice	O
chat	O
,	O
and	O
calling	O
with	O
yuilop.me	O
.	O
</s>
<s>
Yuilop	B-Protocol
's	O
text	O
chat	O
client	O
allows	O
group	O
chats	O
,	O
emoticons	O
,	O
photo	O
sharing	O
,	O
and	O
location	O
sharing	O
.	O
</s>
<s>
Yuilop.me	O
is	O
an	O
option	O
to	O
receive	O
a	O
virtual	O
mobile	O
phone	O
number	O
.	O
</s>
<s>
Yuilop.me	O
is	O
currently	O
available	O
to	O
Yuilop	B-Protocol
users	O
in	O
the	O
United	O
States	O
,	O
the	O
United	O
Kingdom	O
,	O
Germany	O
and	O
Spain	O
.	O
</s>
<s>
Calls	O
and	O
instant	B-Application
messages	I-Application
made	O
to	O
other	O
Yuilop	B-Protocol
users	O
via	O
the	O
app	O
are	O
free	O
and	O
unlimited	O
.	O
</s>
<s>
Calls	O
and	O
SMS	B-Device
made	O
to	O
mobile	O
phones	O
and	O
land	B-Application
lines	I-Application
use	O
"	O
credits	O
"	O
.	O
</s>
<s>
Inviting	O
friends	O
and	O
having	O
them	O
sign	O
up	O
to	O
become	O
users	O
of	O
Yuilop	B-Protocol
.	O
</s>
<s>
Redeeming	O
voucher	O
codes	O
shared	O
on	O
Yuilop	B-Protocol
's	O
Facebook	B-Application
and	O
Twitter	B-Application
accounts	I-Application
.	O
</s>
<s>
receiving	O
chats	O
from	O
other	O
Yuilop	B-Protocol
users	O
,	O
receiving	O
calls	O
,	O
and	O
receiving	O
SMS	B-Device
to	O
a	O
yuilop.me	O
number	O
.	O
</s>
<s>
Version	O
1.9	O
of	O
the	O
iOS	B-Application
app	O
also	O
allows	O
users	O
to	O
purchase	O
credits	O
.	O
</s>
<s>
The	O
number	O
of	O
credits	O
used	O
to	O
call	O
mobile	O
phone	O
and	O
land	B-Application
lines	I-Application
is	O
determined	O
by	O
the	O
location	O
to	O
which	O
the	O
call	O
or	O
SMS	B-Device
is	O
sent	O
.	O
</s>
<s>
Sending	O
calls	O
or	O
SMS	B-Device
to	O
mobile	O
phones	O
requires	O
no	O
credit	O
in	O
or	O
between	O
some	O
countries	O
,	O
such	O
as	O
the	O
United	O
States	O
.	O
</s>
<s>
Yuilop	B-Protocol
used	O
a	O
2048	O
bit	O
encryption	O
to	O
encrypt	O
data	O
traffic	O
and	O
call	O
signalling	O
over	O
any	O
transport	O
medium	O
(	O
Wi-Fi	O
,	O
2G	O
,	O
3G	B-Architecture
,	O
4G	O
LTE	O
)	O
.	O
</s>
<s>
A	O
STARTTLS	B-Protocol
extension	O
is	O
used	O
through	O
a	O
Transport	B-Protocol
Layer	I-Protocol
Security	I-Protocol
protocol	I-Protocol
.	O
</s>
