Jun 11 2011

AppSpin: VOIP – free calls on your iPhone

Would you like to make free calls from your iPhone?

There are a number of apps that allow VOIP calls from an iPhone. Today, Robyn showed me Viber.

VOIP stands for Voice over IP. It is the protocol used to transmit voice over the Internet – the most famous implementation of which is Skype.

Are VOIP calls free?

If you are calling from one VOIP user to another, a la Skype, then there is no charge for that call, apart from the usual data charges associated with using the Internet.

Therefore the best time to use VOIP is when you have a Wifi connection, particularly is someone else is paying for it. You may be able to log on to a free wireless network, such as at McDonalds and other cafes. Sydney Airport now has free Wireless Internet, as does some Sydney Public Transport. If you have a Wifi connection at home, you will be paying some charge for the data you use. You will usually have spare capacity in your broadband ‘cap’, which then makes the marginal cost of VOIP free. 

Generally, the cost of the internet data will be less than the cost of a regular phone call.

You can make a VOIP call from your iPhone without a Wifi connection, in which case you will be using some of your 3G data allowance. For many of us, there is plenty of spare capacity before we reach the ‘cap’. However, the amount of data you use is something to keep an eye on. 

If you have a free WiFi connection, using VOIP while overseas is fantastic. However, don’t use VOIP overseas through a roaming 3G connection – data charges can be astronomical.

There are a number of competing VOIP networks with iPhone apps.

I looked at Facetime, Skype, Truphone and Viber today. 

VOIP is most effective when you call someone else who uses the same VOIP network – So Skype to Skype, for example. Truphone and Skype both allow you to make cheap calls to normal landlines or mobile phones, using a PrePaid model. You need to have credit in your Truphone or Skype account to enable this.



Facetime comes pre-installed on iPhone4 and iPad2, and is not available for iPhone 3GS and iPad. It is also available on an iMac or MacBook.

On an iPhone, users are identified by the phone number. On an iPad or Mac, by their email address.

It is available over WiFi only – and will not work if either user is on 3G.

Incoming calls will ‘ring’ even if the Facetime app is not running.

In the limited circumstances when you and the person you wish to video call are both using an iPhone4, iPad2 or Mac, and are within a WiFi network, Facetime is effective and easy to use.



Skype is the market leader in VOIP, and is available on the iPhone and iPad, as well as for Mac and Windows desktops and laptops. Skype allows conference calls and video calls, and works over WiFi and 3G. You can make ‘SkypeOut’ calls to normal landlines or mobile phones if you have prepaid some Skype credit. These calls are very cheap, particularly when calling from overseas.

Skype users have to register a username and password to be part of the Skype system.

On the iPhone, incoming calls will ‘ring’ only if Skype is running in the background ie the user will have had to have opened the Skype app each time they turn their phone on.



Viber is a relative new comer to the field, and is iPhone only.

It is very easy to set up – users are identified by their mobile phone numbers, and on first using the network are sent a ‘one time’ security code via SMS.

The Viber App emulates the usual iPhone app almost exactly. It is clearly indicated if someone in your contact list is also on the Viber network. 

Viber works over WiFi and 3G. I have found the quality of sound on the calls to be very good.

Incoming calls to a Viber user will ‘ring’ even in the app is not running in the background. That is a very significant advantage.


Truphone, like Skype, is available on most phones and desktop systems. Like Skype, you can use it to make cheap calls to landline and normal mobile phones.

To receive an incoming call on the iPhone, the app has to be open and running in the foreground! This is a show-stopper for incoming free VOIP calls.


I think Facetime, Skype and Viber all have a place on your iPhone. To a very large extent, it depends on what your contacts are also using.

Viber is particularly good for iPhone to iPhone calls, when both caller and recipient have installed the app – it is very easy to set up and use.

I keep credit in my SkypeOut account, and use Skype when away for long distance calls to normal phones,and for Video calls back home when not on a WiFi network

FaceTime is good for video calls when on WiFi.



Leave a Reply

Your email address will not be published. Required fields are marked *