(CBS) — Transit officials are looking for 100 riders willing to test an app that will allow mobile ticketing using smart phones on the CTA, Metra and Pace.

The transit agencies offered reporters a test demonstration Friday of the new Ventra app, which will allow CTA riders to use stored fares on their Ventra cards to buy Metra tickets, work as a train-and-bus tracker and even help plan trips.

If it works as anticipated — and transit officials are already projecting a June launch — it will mark the realization of a 40-year search for a fare card good anywhere on Chicago area mass transit.

CTA riders will be able to tap their smart phones to pay for rides, add value to their Ventra accounts and store fares or passes. The app will be made available only to those riders who have iPhones and Android smart phones, but not BlackBerry devices.

The CTA’s manager of external electronic communications, Tony Coppoletta, said the feature he likes best is the ability to use stored CA fares to buy a Metra ticket.

“If I’m in Hyde Park and decide I want to take the Metra Electric downtown, I can pay over the phone and show the conductor,” he said.

Metra will be able to prevent fraud several ways, says Jeff Brantz, Metra’s manager of schedules and services.

Riders will be able to buy one or more Metra tickets at once, keeping them in a smart phone “wallet.”  Each ticket that is activated must be done separately; by asking if you intend to use the ticket it will prevent riders from inadvertently launching several tickets at once.

The ability to buy tickets using smart phones on board is an attempt to minimize the amount of fare collection conductors must do. Based on recent surveys, Metra estimates that 80 percent of its riders use smart phones.

Those who opt to activate the debit Master Card function of Ventra cards will be able to use them to buy Metra fares through Metra ticket windows, although Brantz said the app is a way to avoid the ticket window altogether.

Bus and train tracker information from all three agencies will be available in real time through the app, a first for Pace riders, showing the next five buses or trains.

CTA spokesperson Tammy Chase said that for its test, which begins immediately, the transit agencies seek 100 riders who are regulars, and preferably riders who make use of two of the three agencies — Metra and CTA or Pace. Riders can sign up to be considered at each agency’s Web site; the agencies seek riders who also are willing to test specific improvements and are not afraid to give feedback.