Steam has joined the masses of mobile apps available to users of those touch screeny things that people are always using. The idea is to allow people Steam functionality on the go. Where they are going, we know not, but apparently they need access to Steam on the journey. Valve had this to say about the move to mobile devices:

With the Steam app, gamers around the world may chat with Steam friends, browse community groups and user profiles, view screenshots and user-generated content for their favorite games, read the latest gaming news, stay up to date on unbeatable Steam sales, and more.

If you want to be part of the beta, you can download the app from this here linky.