Orbitz adds mobile-only promotion for Android users By Danny King / October 24, 2012 Share 1 -- Orbitz, which already offers discounts of as much as 50% off published hotel rates for iPhone users, added a similar application for Android phone users. The online travel agency's Hotels by Orbitz is a free app on Google Play that lets travelers choose from as many as 240 markets worldwide for their potential discounts. The promotion reflects the growing popularity among travelers of using iPhones, Android phones and tablet computers to research and book applications. Some researchers and travel intermediaries have estimated that mobile-based bookings have at least doubled in the past year and will continue to grow rapidly. Orbitz follows larger online travel agencies Priceline and Expedia in its offering of mobile-only discounts. Expedia in August started offering mobile-only discounts of as much as 30% off published rates at more than 2,000 hotels across North America and Europe. And last September, Priceline started its "Tonight Only" promotion that lets mobile users get exclusive rights to same-day discounts of as much as 35% off of three- and four-star hotel rooms in select cities. Expedia accounts for about 40% of the travel that Americans book on OTAs, or about double Orbitz's market share, according to PhoCusWright. Follow Danny King on Twitter @dktravelweekly.