Wait-app systems stemmed from the realization that everybody already has a pager of their own--their phone--that isn't bound by range and that can provide added information. Many of the apps target the service industry, which provides a wealth of opportunity: Online reservations service OpenTable made $140 million via its deals with more than 17,000 restaurants in 2011, and its market is limited to establishments that take reservations.
Nearly all wait apps share two features: They send text messages when tables are ready, and they provide access--either via an app or a web client--to a real-time visualization of the virtual line so customers can see how far back they are. "Expectation is a huge factor in determining whether a person will wait," explains Larson. "If someone expects to wait 15 minutes and it grows to 30, he'll be furious. If he knows where he stands, he's more likely to stay."