Cashlog system even works over a wi-fi connection.
Like a number of others (Neomobile,TIMwe), Buongiorno has spent the last couple of years diversifying away from pure content and into mobile commerce.
Its Cashlog 'pay by mobile' platform was launched in May 2011 and is now available in Italy, Spain, Germany and France.
It has 40 European merchant partners, has been used by over 150,000 customers to buy digital goods, and processed more than 1.7million transactions in May 2012.
Now, Buongiorno has extended its functionality to support one click in-app operator payments on Android. The SDK's automatic number recognition works for any SIM-based device not only in the 3G network but also via wi-fi.
It is live in Italy, Spain, Germany and France and has connections with 15 operators.
The firm reckons 12,000 of the 464,000 apps in Google Play have in-app billing features. Operator billing has been shown to increase transactions when compared to credit cards.
Guido Mangiagalli, head of cashlog, said: “The 1 click buy experience over wi-fi is the competitive advantage of Cashlog’s Android in-app solution, considering that the majority of users connect to the mobile internet this way.
"We worked hard to make the experience the same as if you are in 3G: seamless, fast and secure. We are confident that our Android in-app solution will further increase successful sales for merchants.”
Cashlog launched an in-app purchase option for HTML5 apps in January.