He began working with fellow Wharton students Mark Kozlowski, 27, and Ted Lui, 27, to evaluate other ideas: An app that would integrate with bars' point-of-sale systems, maybe, or an app that would allow users to order in advance so their drinks would be waiting for them. (Both had drawbacks: there are too many kinds of such systems in use, and too many variables - melting ice, potential tampering - with making drinks in advance).