Joining companies such as Amaysim and Internode, Adam Internet's AdamMobile service offers BYO phone, SIM only mobile plans starting at $15 per month.
Like Amaysim, AdamMobile uses the Optus 3G network.
Where Internode's NodeMobile is only offered to users of Internode fixed-location services, AdamMobile is open to any resident of South Australia.
"With the launch of AdamMobile we can now offer the full range of communication and entertainment services to our customers including internet, fetchtv, AdamTalk, our VOIP service - and now AdamMobile," said executive chairman Greg Hicks.
"We are pleased to offer the great quality of service powered by the Optus Network, while enabling our customers to benefit from our local presence and customer service," he added.
The $15 plan provides $80 worth of calls and SMS (priced at 35c flagfall plus 90c per minute, 25c SMS to Australian mobiles), 100MB of data (any excess is charged at 50c per megabyte) and free access to Facebook, Twitter, LinkedIn, Myspace, eBay and Foursquare (subject to various limitations).
Existing numbers can be ported to AdamMobile, but nano SIMs are not currently available.