App begat app Saturday, as Westport Public Library patrons shared -- or, "slammed" -- details about their favorite applications for electronic devices.

The library's annual "App Slam" was a literal free-for-all, as Bill Derry, the library's assistant director and veritable technology wizard of Westport, introduced a range of unique and useful tools available, most for free.

"Did you ever hear of a poetry slam," Derry said, "where the people come in and do their poetry? Well, this is a takeoff of a poetry slam."

About two dozen people were drawn into the enthusiastic discussion and demonstrations of online application tools -- everything from traffic and music apps, to one that allows the user to identify planes that are flying overhead and another that offers free music downloads through the library.

"There are great calorie-counting apps," Derry said. "There are great travel apps ... If you're into photography there are so many better apps for your camera ... I've got many radio apps ..."

Attendees also shared their favorites.

"I have one that I spend way too much time on," called iSpy, said Kevin Carroll of Westport. "It costs a dollar and (it's) over 2,000 live videos cameras from around the world. Some of the ones I spend too much time on are a bakery in the Caribbean, a ski area in Sweden ... the Vatican (and) a tattoo parlor in Russia."

"And most of the cameras you can control... so you can control cameras five thousand miles away, and most of the cameras are hi-def," he said.

Norman Tsang of Westport shared an app called "Where's Our School Bus?," which enables parents and students to not only know whether their bus is on time, but estimate its location and get a sense of whether the bus is on its route.

"It's to reduce anxiety," he said, and also helps to saves gas if the user thinks the school bus may have already come, when it's merely late.

"It's a crowd-sourcing application," Tsang said. "The idea is that you have to have a number of people using it to make it useful."

But, he said, "There's just a nice way of communicating (and) once a few people join in, it's amazing how useful it can become."

"It's free to the user and we've already paid for these phones," he said, "so we might as well get the most out of them."

Derry said the App Slam itself has proved to be a valuable way of helping people put a personal spin on the technology age. "It's another social way of sharing," he said. "It brings people together. That's what the library tries to do."

Derry shared a variety of his favorite apps, including Cardmunch, which allows the user to photograph a business card and store all the information in a database, with links automatically created as well.

"If the person is on Linked-In, you get the information on the person that is in Linked-In," he said.

Another app, which people can access through the library, is Freegal, which allows patrons to download three free songs every week from the database and keep them permanently.

Another worthwhile app, Derry said, is called Appsgonefree. "Every day you get a listing of apps that up until the day before, or recently, you had to pay for, and now they've put them in the public domain," he said.

"I liked being exposed to all the new, free apps that are available," said Mary Harris of Westport. "I thought this was excellent."

"I thought it was spectacular," said Jim Coyne of Westport, "because in a short period of time I've learned more than I've learned in the entire year and a half I've had my phone regarding apps."