Rebtel launched in 2006 and in 10 years has grown to a turnover of $80M, operating out of Stockholm. In 2016 the company decided to take the next step and is now focusing on high growth with a goal to being the world's largest international calling company.

Rebtel states it is one of the most successful companies for international calling, and strives for an "automagic" experience where customers understand what they are paying for.

Rebtel provides app for iOS and Android, as you would expect, and pleasantly, for Windows Phone also. Rebtel recently launched an update to its app which includes WiFi-free unlimited app-to-app calling. This is free for the remainder of 2016 - so get in now - and will be $1/month thereafter. For Australian users that's $1.30/month.

To clarify, that's WiFi-free, not "WiFi free". The calls do not require you to be connected to the Internet. Unlike traditional VoIP apps, Rebtel can leverage its existing international calling infrastructure to allow you to make cheap international calls via the telephone network - free from drop-outs, data fees and disconnections.

If you have used Skype, Lync, or many other varied VoIP apps in the past then you already know how to use Rebtel. However, Rebtel is backed with crystal-clear calling and an unswerving philosophy to making the user experience simple. The app is gorgeous and a pleasure to use, and allows effortless calling to any number in the world at cheap rates.

For international travellers there is no need to dial a gateway first, no need to deal with calling cards, and certainly no concerns about international calling fees. Nicely, your own number can show on the display of the people you call so they know it is you. Your friends and family and business partners won't be plagued by weird numbers calling them.

You can find call costs and app download links from Rebtel's web site. Sign up for free call credits to try it out, and then use the app-to-app feature for no charge for the rest of 2016 too.