Travel apps have been around since smartphones first hit the scene, but in the last couple of a months there have been a number of the big online travel sites have launched apps specific to booking hotel rooms.

Orbitz has a new hotel booking app for Android called Hotels by Orbitz, that helps Android users shop for hotels and get access to mobile-only discounts of up to half off. (The app is already available to iOS users). To promote the new app, Orbitz is running a sale across all of its mobile apps through Sunday. Book a hotel using one of the Orbitz apps and you’ll get 10% off.

Earlier this month, Hotwire released its Hotwire Hotels app and last month, Travelocity released the Hotel Deals app, both of which offer special last minute rates.