A web app (no download required) is now available for iOS along with a native app (free) for Android devices.
A third version of the scheduler is available for other mobile browsers.
What do the mobile apps offer?
[The app] puts all the information right at your fingertips, including your existing schedule, list of exhibitors and personal notes from the full Scheduler site. Just log in with the same username and password you use on the Scheduler to access all of your existing conference information.
Highlights of the Scheduler include: multiple ways to browse sessions and events and ease of adding, prioritizing and updating them; an easy-to-create personal schedule that can be shared or kept private; tailored lists of recommendations based on division, groups, library type and interests specified in the user profile; ease of adding booth visits and meetings with specific exhibitors; finding an attendee to send a personal message; and getting word on any session or program cancellations.