Why do you need a mobile web app for your attendees ?
I attended last RailsConf 2013 in Portland, OR. I needed to create my own schedule, as there were multiple talks at a time, but the official mobile app wasn't able to do this and was not really usable. So I created one. Your attendees have the same need.
Features
Browse talks and full schedule offline
See the #twitter feed of your conference
Let your users mark favorite talks and have a custom schedule
See speaker details
Browse conference details like location, hours, organization team...
Free Version for any non-profit conferences
If you are a non-profit organization, you can use it for free. You have to follow the instructions and host it yourself.
Premium Version for only 299$
Take your conference to the next level with the premium plan.
With the premium plan, you will get a custom theme with your conference's colour scheme, unlimited 24hr support, easy, painless setup, and your application will be hosted on a new domain if you want to, or you can host it on your server. Your application can also be published on the App Store and Google Play Android for an extra $49.