Kate O’Reilly’s spring allergy survival kit includes the usual stuff — nasal sprays, allergy pills and a box of tissues. This season, she’s added a new weapon to her line of defense: an app on her smartphone.

After waking up one recent morning with a stuffy nose and stinging eyes, she downloaded the WebMD Allergy app, which tracks pollen levels in the air.

"If there’s a high level, I want to wake up knowing that," said O’Reilly, of Minneapolis.

The prolonged winter delayed the start of allergy season, which typically begins in March. While that gave allergy sufferers some relief, allergists say their offices now are bustling as allergy season kicks into high gear.

Allergy apps are just starting to bloom. Many of them have been developed in the last year, said social media expert Christopher Lower, who contends that the new apps are a spinoff of the wildly popular weather apps.

These apps are beginning to change the way some people manage their seasonal allergies, which afflict up to 25 percent of the population. But some allergists are skeptical about the apps’ usefulness.

Common features of the often-free allergy apps include a daily forecast of the pollen levels in your area and a description of the predominant allergens in the air — tree pollen, grass, mold and ragweed, to name a few.

Many apps also allow users to log their symptoms and medications. For example, Zyrtec makes an AllergyCast app with a "Today I feel" dial that allows users to choose from "ugh" to "great." It also features a "products" tab that lists various medications, made by Zyrtec, of course.

Dr. Ron Reilkoff, a pulmonologist and assistant professor at the University of Minnesota, said he sees benefits in using apps to measure air quality.

"All these allergies depend on the environment," he said, "so if you can be forewarned and be prepared that it’s going to be a bad day … I think it’s beneficial."

Dr. Julia Montejo, an allergist with Fairview Clinics, agreed. She said the apps can be particularly helpful for people who don’t recognize their symptoms.

"I think they’re useful if they can help guide your therapy," she said. "For some people, if they have runny noses and sneezes, and they’re wondering if they have a cold or an allergy, they can probably figure out that it’s an allergy if they see pollen counts. So then they’ll say, ‘Oh, today is a Claritin day, not a Sudafed day.’"

Catie Kennedy of Minneapolis has been using an allergy app for several months. "I find it incredibly useful," she said. "I’d rather know what I’m up against than not."

Her app sends her special alerts when pollen levels are especially high. "I take an allergy pill every day as soon as I start getting these alerts," she said.

But not everyone is so eager to welcome the apps. At the Allina Medical Clinic in Woodbury, Minn., Dr. Pramod Kelkar said that many factors beside pollen levels influence allergies.

"It’s kind of intellectually satisfying to look at the apps and look at the pollen count," he said, but, "people should look at their body and their symptoms rather than looking at the apps."

Dr. Philip Halverson questioned the tool’s usefulness as well. "I wonder about the clinical utility of pollen counts," he said. People with allergies who are seeing doctors already are treating their symptoms. "If it’s a seasonal allergy, we typically have a plan," he said. "So, really, the treatment is pretty much symptom-based."

Allergy apps aren’t on most people’s radar yet, said Lower, co-owner of Sterling Cross Communications in Maple Grove, Minn., but they’re a natural outgrowth of mainstream apps. He cited a recent Pew Research Center report on smartphone apps, which found that weather-related apps top the list of mobile downloads. "That’s typically where most of these (allergy) apps came out of — they’re gaining mass information from weather sites," he said.

O’Reilly had a weather app, but was looking for more information about pollen. So, she turned to what’s become a reliable source: her smartphone. She tweeted: "I wish weather apps had an allergy component. Is there a seasonal allergy app?" She instantly received a half dozen responses on Twitter.

Kennedy chimed in, tweeting: "The Weather Channel App for iPhone does. There are even alerts!"

O’Reilly ultimately chose the WebMD Allergy app. It has bar graphs showing pollen levels, ranging from none to low to moderate to high and finally severe. "It’s almost like a ‘threat level green,’ ‘threat level orange’ situation," she said, laughing. "I liked it right away."