British bookmaker William Hill launched its iPhone app in February 2012, and announced today that it’s been downloaded more than half a million times.

The milestone came as the company launched a companion app on iPad, providing tablet access to football, horse racing and other sports betting. William Hill says that apps currently account for 30% of all its online betting – a proportion that may be boosted by the new tablet app.

“Mobile betting is booming, with more customers using our service as a second screen solution to watch sport at home or on the move,” said director of mobile Juergen Reutter in a statement.

“We anticipate the service becoming even more popular over the festive period and are sure the simple, easy and convenient functionality of the app will become a favourite way for many of our customers to bet.”

William Hill certainly isn’t the only company setting its sights on tablet gambling: Betfair has had an iPad app for some time, as have Betfred, Paddy Power, Sky Bet and Bet365.