The Typo Keyboard, an iPhone accessory backed by “American Idol” host Ryan Seacrest, is scheduled to ship to customers by the end of the month after the product sold out of its initial inventory.

The device, which debuted at last week’s International Consumer Electronics Show, lets users attach a BlackBerry-style keyboard to the iPhone 5 and 5s. The startup behind the $99 product, Typo Products LLC, expects to ship new orders by the end of February, according to a statement today.

Tech guru Walt Mossberg, who recently left The Wall Street Journal to start a new website called Re/code, likes the device.

“I’ve been testing the Typo keyboard, and can recommend it for physical keyboard die-hards,” he wrote in comments reprinted at MacDailyNews. “It has some trade-offs, and won’t likely appeal to most iPhone users who never became thumb-typing wizards. But those who miss physical keyboards will love this thing.”

BlackBerry, the Canadian smartphone maker, sued Typo Products earlier this month, alleging it copied its designs for the keyboard. The product infringes patents and designs used in the Q10, a keyboard-equipped phone that BlackBerry released last year, according to the complaint.

“We’re excited about all of the positive feedback Typo has generated and we’re working hard to ensure that we get as many keyboards in consumers hands as soon as possible,” said Typo Chief Executive Officer Laurence Hallier, who co-founded the Los Angeles-based company with Seacrest.

The Typo is designed to appeal to iPhone customers who miss having a physical keyboard. The product slides onto the phone, adding a quarter-inch of thickness (less than 1 centimeter) and three-quarters of an inch in length. Pre-orders for the accessory that were received before Jan. 12 will ship this month, the company said.

Return to Roots

BlackBerry, meanwhile, has made physical keyboards a focal point of its comeback plans — following a foray into touch- screen phones that fizzled with consumers. In the future, the company’s phones will “predominantly” have keyboards, CEO John Chen said in an interview last week.

Keyboard phones have long been popular with corporate and government users, who rely on them to hammer out e-mails. Those customers fueled BlackBerry’s early success, though many converted to touch-screen Apple Inc. and Android devices in recent years.

BlackBerry’s share of the global smartphone market tumbled to just 1.7 percent in the third quarter, from 4.1 percent a year earlier, according to research firm IDC.