Firefox OS app developers hoping to snag one of the new Firefox OS phones seem to be out of luck.

The Keon and the Peak popped up for sale today courtesy of manufacturer/seller Geeksphone. But the two phones already appear on the company's Web site as "out of stock." The page for each phone simply says "this product is no longer in stock" with no further explanation.

Screenshot by Lance Whitney/CNET

A spokeswoman for Geeksphone told CNET at around 6:15 a.m. PT that the phones are currently out of stock due to great demand. But the online sale is expected to restart in the coming hours.

The Peak was available earlier in the day, while the Keon sold out more quickly. Priced at $119, the Keon is the budget-oriented model with a 3.5-inch 480x320-pixel screen. At $195, the Peak offers a 4.3-inch 960x540-pixel multitouch screen.

Geeksphone is the only source for the Mozilla OS phones at this point.

The two Firefox OS phones aren't meant for consumers; rather they're designed for developers who want working models to test their apps for Mozilla's mobile operating system.

Mainstream Firefox OS phones are expected to be manufactured by such companies as ZTE, Alcatel, LG Electronics, and Huawei for release next year. Sony is also eyeing a Firefox OS phone for 2014.

Mozilla's goal behind Firefox OS is to offer low-cost phones and other devices that will appeal to consumers in developing markets.

Updated at 6:30 a.m. PT with response from Geeksphone.

Correction at 9:57 a.m. PT: The story incorrectly described Geeksphone. It is a manufacturer and seller.