Leap Wireless today announced the launch of its LTE service in a number of new markets, including Philadelphia and Phoenix, as well as Houston, San Antonio, Austin, Laredo, Corpus Christi and Brownsville-McAllen-Harlingen, Texas.

The Company also announced the introduction of its first two 4G LTE smartphones, the LG Optimus Regard ($249) and the Samsung Galaxy S III ($549), along with new LTE smartphone plans.

Today's announcement completes what Leap is calling "the first phase" of the company's introduction of LTE technology. Until now, Leap has only offered LTE service in Tucson, Ariz. and Las Vegas, NV, which launched in 2011, and October 2012 respectively.

The company said in a statement that its LTE service now covers approximately 21 million potential customers across 11 markets.

Leap has held some spectrum in reserves in anticipation of rolling out LTE. The company reports that pre-launch speed tests conducted in the markets launching today under the Cricket brand ranged up to 15 times faster than current Cricket 3G data speeds, depending on market conditions.

Both the LG Optimus Regard and the Samsung Galaxy S III will be available with "Double Data" service plans that offer, for a limited time, double the monthly full speed data allowance offered in its 3G rate plans. The $50 LTE Android Double Data Rate Plan allows 2GB of full-speed data, while the $60 plan allows 5GB of full-speed data, and the $70 plan offers 10GB of full-speed data.

Muve Music will not be available at launch on the LG Optimus Regard or the Samsung Galaxy S III, but is expected be available on in December on those devices via over-the-air download.

Earlier this year, Leap signed up for wholesale access to Clearwire's still unbuilt TD-LTE network to add coverage and capacity to its own LTE service.

Leap has consistently said that it is continuing to look for cost-effective ways to expand its LTE coverage, which could include deploying facilities-based coverage and by entering into partnerships or joint ventures with other carriers.

Leap reported losing 269,000 net customers in the third quarter, as churn rose a full percentage point to 4.8 percent, contributing to a 2 percent decline in its customer base.

Leap now has 5.6 million customers, down from 5.75 million last year.