Trackle, a start-up that delivers personalized Web alerts, is back in business after a human error and surge of traffic to the newly unveiled public beta test caused the site to crash Tuesday.

Trackle lets users create free customized alerts for last-minute flight deals, cheap apartment rentals, celebrity gossip or updates from members of their LinkedIn network.

“I found myself repeatedly was going to the same Web sites looking for what’s new,” said Pavan Nigam, chief executive and founder of Trackle. “It occurred to me there needed to be a centralized place to track everything.”

Services like Google Alerts, Yotify and Notify.me already offer similar scouting tools, but what sets Trackle apart is the broad range of its alerts. For example, Trackle members can set up alerts for a mention of their names, classified listings on Craigslist, updates on the latest salmonella outbreak from the Food and Drug Administration, local crime news or a friend posting a link to their Facebook page.