SAN ANTONIO, Tex. (CBS/KENS) -- Some smartphone users are buzzing about an app that they believe keeps the mosquitoes from buzzing in their ears. There are several smartphone apps that claim to produce an ultrasonic sound not audible to the human ear, but a sound that scares mosquitoes away. Some of the apps have been downloaded by millions with high reviews. Some experts are skeptical.

They're searching for your blood, leaving you itching and sometimes just looking at mosquitoes makes you scratch. But now the best repellent could be in your pocket.

That's right, a mosquito repellent app that claims to produce an ultrasonic sound so high pitched its undetectable to the human ear, but makes a sound that scares mosquitoes away. It's been downloaded by millions with high reviews, but does it really work? San Antonio entomologist Molly Keck says, "There's no scientific research as of now to prove that it does or doesn't work, there's just no reason why it should."

Keck is skeptical of the app saying mosquitoes don't hear like humans so she can't see how it repels them. She says, "Most of the time mosquitoes and all insects smell and hear through scents and chemicals in the air and not through wave lengths."

But usually apps that don't work well, get bad ratings and aren't downloaded, which means until its scientifically proven not to work. This app will most likely continue buzzing. Keck says, "It's surprising but people are going to believe what they're going to believe and can you can't argue with success, if it works for you then it works. Its free so I think you get what you pay for, so download it, you're not out any money if it doesn't' work for you"

Now some say if you use the app, be warned the high pitched noise could also be irritating to your dog or cat if you have them.