SAN FRANCISCO — Microsoft on Monday unveiled software that lets Twitter, Facebook and other hot Internet services be delivered to low-cost “feature phones” common in developing countries.

The U.S. technology giant will debut OneApp in South Africa and hopes to swiftly roll it out in India, China and other countries where millions of people use feature phones instead of powerful smartphones.

“We designed OneApp from the ground up on feature phones with very limited memory and processing capabilities,” said Amit Mital, corporate vice-president of the Unlimited Potential Group and Startup Business Accelerator at Microsoft.

”OneApp will be able to help people do things they couldn’t do before with their feature phone — anything from paying their bills to helping diagnose their health issues or just staying connected with family and friends.”

Feature phones typically combine calling capabilities with one or two other functions such as playing music or games.

Such devices rely on General Packet Radio Service (GPRS) networks with users unable to browse the Internet and typically paying to download data.

In contrast, smartphones are essentially pocket-sized computers with wireless Internet connectivity.

”With a GPRS-enabled cellphone, consumers can now be part of the app experience,” said Mark Levy, joint chief executive of Blue Label Telecoms.

Microsoft teamed up with Blue Label Telecoms to make OneApp part of a new “mibli” mobile service to be offered free in South Africa, said Mital.