YPlan is filling a niche for users who want to buy tickets for events at the last minute via smartphones. The free application has been downloaded about 500,000 times in its first year and resides on about 15% of Londoners' smartphones, the first city to host the application. New York came next for the developers, but a "human capital" issue is prohibiting its spread to other cities. "The way that we do it is, one city at a time, do it properly, do it well. That means that every time before we launch a new city, we have to put in some ground work," CEO Rytis Vitkauskas says.