CHICAGO (CBS) — The Ventra smart phone app is off to a fast start.

By mid-afternoon Thursday, the first day it was available to the general public, more than 20,000 people had downloaded the free app and it was the #3 trending app at The App Store.

A CTA spokesman said the response was “overwhelmingly positive,” a sharp change from the problems that plagued the introduction of the Ventra card for months.

Statistics tabulated by the CTA indicated that, by mid-afternoon Thursday, riders had created 5,000 new Ventra accounts and that more than 1,300 riders had used the function that allows riders to buy, store and use Metra tickets; in all, riders had bought and stored 9,600 rides, showing that many had purchased 10-ride tickets using the app.

Introduction of the app marks the first time that a single fare payment system has been usable for rides anywhere on the CTA, Metra and Pace systems. The RTA searched for nearly 40 years for a usable universal fare card but was unable to find an answer before this. Instead of a card, it utilizes iPhone and Android apps.

In addition to purchasing Metra tickets, the app allows riders to manage and add money to their Ventra accounts, get real-time information on trains and buses run by all three agencies and plan trips using Metra.

CTA hopes to introduce a “swipe and go” feature on an upgrade, possibly in the next year.

As might be expected, RTA Chairman Kirk Dillard is a big fan. He calls the app’s abilities “mind-boggling,” said his son finds it to be “really cool” and said, “If I can use it, anyone can use it.”

“Really, you don’t need to have your wallet anymore,” he said.

A few riders tweeted to report problems accessing existing Ventra accounts through the app, but a CTA spokesman said the problem has been traced to older smart phone operating systems — and fixed.