Nashua Mobile has announced plans to expand its flat-rate Xtreme Data service to more phones.

Launched in March this year as an alternative to the BlackBerry Internet Service, Xtreme Data from Nashua Mobile is a fixed-cost data service priced at R59 per month. The flat-rate service – currently available for a range of Nokia devices - offers customers data for email, Facebook, Twitter, WhatsApp, browsing and more.

The package will hit the Nokia Asha 300, 303 and 201, Nashua Mobile announced.

"This is great news for users who don’t want to spend much more than R200 a month (including data) on their smartphones," a press statement read.

The company has also unveiled its Xtreme Data Premium offering for the Lumia 900, 800, 710 and 610.

At R139 per month, the Premium Xtreme Data service has a soft cap of 400MBs of high-speed data before the Average Use Policy (AUP) kicks in and the data service is throttled or shaped. The standard Xtreme Data option has a 100MB soft cap.

"Consumers will also be happy to know YouTube is not blocked on the Xtreme Data Premium service – unlike the standard service."

In most cases, you will only notice the slower download speed when you are streaming data or downloading apps, the company said.

"For everyday services like WhatsApp, Email, Facebook and browsing, you will still enjoy a fantastic user experience."

The Xtreme Data service is currently exclusive to Nokia devices, but customers can look forward to other platforms being added to the service soon.