Only the current version so far — new entries appear as the app ships updates.
Check In Help - Event Callin is an education app by Clancy Systems International, Inc. with 1,000+ downloads (about 2.9K estimated). Rated 5.0 from 7 ratings. Released Jun 22, 2012. Install growth, rank history, SDKs and ad networks.
From the store listing: “This app allows each CME event-goer to register themself using Event Callin”