Microsoft has announced the official launch of OneApp, a small application that provides easy access to popular web services for feature phones. With services like Twitter, Windows Live Messenger and Facebook typically only easily available to smartphone users, OneApp reduces data usage by allowing Microsoft servers to handle the most demanding aspects of surfing such service sites.

OneApp itself weighs in at only 150KB with each service addon requiring an addition 30KB, allowing low-spec feature phones to take advantage of a robust application without the typical space requirements. OneApp will also allow developers to easily build small applications around it, providing instant compatibility across a range of phones.

Microsoft also says that OneApp support will make it easier for developers to build applications for feature phones, since an app need only be developed once for OneApp and it will then run on a very wide variety of phones as a result.

The first carrier to offer OneApp to its customers will be Blue Label Telecom in South Africa as it rolls out the service to its “Mibli” service subscribers next month.