For teen tech whiz, Trisha Prabhu, being a high school science nerd is actually kind of cool.

She’s traveled the world sharing her ideas and was even a headliner at TEDxTeen talk about the problem of cyber bullying. But now she’s got an app for that.

Over the past two years, Prabhu, 15, has been developing ReThink, an app to make cyber bullies think twice before sending a hurtful text or tweet.

“ReThink is able to detect when someone tries to post something offensive on social media and then alert that person and go, ‘Whoa. Hold on. Are you really sure you want to post message? It could be offensive,’” Prabhu told ABC News.

The alert appears as a pop-up window on the screen.

“We’re giving them a chance to rethink their decision, at which point they can either hit clear, ‘Maybe I do want to think about this,’ or they can go ahead and decide that they want to post the message,” said Prabhu.

The app is built with a growing database of trigger words and phrases that could be offensive and the sophisticated program is intuitive.

“ReThink is able to understand the difference between ‘I hate Chicago’s weather,’ and ‘I hate you,’ because those are two different scenarios,” she explained.

Prabhu, whose parents are both in computer science, started coding at age 10.

The idea for ReThink was born when she learned about 12-year-old Rebecca Sedwick, who committed suicide after allegedly being cyberbullied by two classmates.

Prabhu’s insatiable intellect led her to medical studies on the teenage brain which show that the part of the brain that regulates impulse control is not fully developed in teenagers.

“The adolescent brain is liken to a car with no brakes, so we don’t think about what we’re doing when we’re posting something,” she said.

Prabhu tested her app on 300 students last year with eye-opening results about what happens when the teenager gets an alert from ReThink.

“The overall willingness to post an offensive message drops from 71 percent to 4 percent,” said Prabhu.

The research won her a coveted spot as a Google Science Fair 2014 Global Finalist.

“I think anything we can do to reinforce the bullies to check themselves and the victims to possibly not be a victim, we’re moving forward,” said Millennial lifestyle expert, Chelsea Krost.

And Prabhu has no plans to profit from ReThink.

“No one should have to pay to be safe on the Internet,” she said.

She says the app, which is already available for Android users, will release an IOS version in the next few weeks.