Jeremy Weaver likes to spend warm summer nights wandering through Texas deserts and pastures armed with a headlamp, three-foot-long tongs, and a pillowcase. He roams the state’s nature conservancy land and wildlife reserves—places like Oasis Ranch on Independence Creek Preserve—to capture, collect data on, photograph, and then release poisonous and nonvenomous snakes.

Weaver’s love of reptiles was sparked through the HHMI undergraduate research program at Texas Tech University, directed by herpetologist Lou Densmore. Now a grad student at Texas Tech with Densmore as his mentor, Weaver specializes in American and Cuban crocodiles, but snakes still captivate him.

Weaver’s wife, Mary Ann, a fourth-year medical student, sometimes joins him on snake-hunting jaunts. “She’s more comfortable with snakes than she used to be, but she’s not a fan of holding them,” he says. Still, last year she suggested that he combine his computer skills with his snake smarts and, just for the fun of it, develop reference apps.

Weaver’s first app, called TX Snakes, has a regional focus, unlike other snake identification apps. It provides detailed, descriptive information, by county, on all 72 recognized species in Texas, including probable ranges of each species within the state’s 254 counties.

So, for example, when Weaver’s friend stumbled across a snake while playing Disc Golf, he entered the snake’s county location and banding pattern in the app. “He was able to identify it as a Southern Copperhead, a common venomous snake in Texas,” says Weaver. “Using a long stick, he encouraged the snake off the golf course so other players would not accidentally step on it or get bitten.”

Weaver usually photographs snakes at night when they’re hunting for food, careful to stay out of striking distance of the venomous ones. “I like to have someone with snake tongs close by so they can wrangle the snake while I take pictures,” he says. “My wife will hold a flashlight, but that’s about as close as she gets to the snakes.” In January, he updated the software with 400 photos of Texas species and subspecies.

Similar apps cost around $10, but Weaver prices his at $1.99 to encourage snake appreciation and respect—and to alleviate fear, especially among parents of young children. “Many people discover they’ve come across a nonvenomous snake they don’t have to kill,” says Weaver, who has a five-month-old son.

Available through iTunes, TX Snakes generates especially brisk sales in the spring and summer months before snakes enter winter hibernation. Downloads the first three months totaled 4,000, for instance, and during the first winter, 1,000. “That’s pretty good for a first app,” he says, adding that plans for a student digital field notebook are on his “to-do” list. But Weaver regards himself as more a hobbyist than an entrepreneur. “I do one computer task each day,” he says, “and this gives me a sense of accomplishment.” Occasionally, buyers grumble that they prefer different common names for certain snakes, but the feedback—“that app saved my life”—is mainly positive.

Weaver is creating other state apps. Thanks to his computer language experience, he produced OK Snakes for Oklahoma and KS Snakes for Kansas in just a few days, but he says, “California will be difficult—it has a ton of snakes.”

Illustration: Ping Zhu