Opera is demonstrating a version of its Opera Mini Web browser for iPad at the Mobile World Congress in Barcelona.

The Opera web browser gained attention last year, when there was some doubt as to whether Apple would allow the app from being distributed via the app store. Opera works differently to most web browsers by utilising a central proxy server.

In effect, instead of connecting to the internet you connect to a central Opera server that caches web pages and delivers them to the app. By caching information and optimising it the Opera web browser can deliver web pages more quickly.

However, it also initially contravened Apple's ban on non Webkit browsers and also there were concerns that it could run external code, also contravening Apple's app store agreement.

An opera spokesperson told Macworld: "It’s not been approved yet by Apple. We expect it to be out soon."

Update: Opera has been in touch to clarify with us that Opera for iPad has not yet been submitted to Apple and that Opera for iPhone was never blocked from the App store, but Apple did take a while to approve it.