HEPCon is an app that has very good integration with the conference service indico. It makes it very easy to navigate the content and it is frankly better than the web interface the system provides. I use the app often and I've noticed that the customer support is almost instantaneous. Review collected by and hosted on G2.com.

The fact that only the conference organizers can enter an event in the app. Review collected by and hosted on G2.com.