Budget airline Ryanair is taking on Skype with the launch of a VoIP app for iOS and Android.

The Ryanair Talk app allows users to make calls by Wi-Fi on their smartphones and tablets and is obviously aimed at travellers: the app’s description says users can “save a fortune on roaming costs when you travel”, for example.

The app itself is free and users can buy credit in flight, when they book a ticket or via the Ryanair Talk website (ryanair-talk.com).

Typically Ryanair, the service boasts of being “cheaper than O2, Vodafone, Orange and Skype” for calls to land lines and mobiles. Ryanair Talk credit is available in denominations of £6.50, £12 and £23, with £6.50 giving 60 minutes to a mobile in France.

What is not clear, however, is if Ryanair Talk customers can make free calls to each other in the same way Skype users can.

The Ryanair Talk service is provided by Wave Crest UK, a specialist in wholesale and retail telephone services.