Republic Wireless, the Raleigh-based provider of national mobile coverage based on a mix of WiFi and cellular technology, is still fine-tuning its $19-a-month unlimited offering.

But the company, which is part of privately held Bandwidth.com, is continuing to generate positive press coverage.

On Monday, Republic sent users a notice that it was incorporating text messaging (SMS) into the WiFi capabilities of the hybrid network.

“This feature will be gradually turned on throughout the week so please don’t be alarmed if you’re unable to use this feature right away,” Republic noted.

Other updates were delivered “over the air” to the Motorola Defy XT phones that Republic sells its customers, including what Republic says will improve WiFi connectivity and sound quality.

Republic is trying to streamline customer support and updates, offering what it calls a “simple drag” and “tap to download” service.

Among early adopters is a reviewer for The new York Times.

“An Android smartphone with unlimited calls, unlimited texting, unlimited data and no contract, all for $19 a month? Really?

“When I first saw this offer from Republic Wireless, I rubbed my eyes and looked for an asterisk leading to fine print that detailed a huge catch. But Republic, a division of a telecom company called Bandwidth.com, delivers exactly what it advertises. It can do so because the handset technology is a curious hybrid: it uses Wi-Fi when the customer is in a Wi-Fi area and Sprint Nextel’s 3G network when it is not.”

So wrote Randall Stross, an author based in Silicon Valley and a professor of business at San Jose State University, in The Times on Jan. 26.