iPad app to register event users

Please NO copy-paste responses. No robots or spammers. Only iPad developers should respond. Don't post anything like: "Our company XYZ has 100s of cool developers who did boa bla boa etc etc. We've done great wordpress websites etc." This project is not about Wordpress or anything else, but iPad development. But If you have any RELEVANT example, please send me your iPad app links. Please don't waste our time. thanks.... So I need someone to build an app that interfaces with Campaign Monitor API to create users, create lists and sort users. How it would work: We have a list of users we invite to an Event. Once they come, we register them and they get into special list. And inside the Campaign Monitor we'll get a separate list of users who came and those who did not come. The app should work with and without internet connection, so once it's online it would sync data with Campaign Monitor API without stopping to function in the Registration mode.