For those suffering from mental health problems, there might be times of need where a seemingly simple task like placing a phone call or sending a text message for help can feel insurmountable, a new app has made reaching out less of an obstacle.

For the one in six Americans who suffer from loneliness, anxiety, depression, stress, suicidal thoughts and other mental illnesses, help is only a tap of a button away, thanks to the young brother and sister team of Hannah and Charlie Lucas.

They’ve created the “notOK” app where users can simply press a button to message up to five contacts about their mental health.

Each contact will receive a text, a link to the user’s current location, and the following notification: “Hey, I’m not OK. Please call me, text me, or come find me.”

“I started passing out more and more often and I was terrified of going anywhere,” Hannah, 15, told ABC News. “Because what if I passed out and no one was around or what if someone took advantage of me?”

After developing POTS, a condition that causes her to faint, Hannah said she was terrified of being alone. What would happen to her if she fainted and no one was around?

Hannah’s fears quickly spiraled into anxiety and deep depression, which led to self-harm. By the end of her freshman year of high school, she missed 196 classes due to her condition.

It was during one of Hannah’s lowest moments, alone in her room and contemplating self-harm, when the idea for the notOK App was born. She thought, what if there was a button she could press, and someone would immediately know she was not OK?

When her condition stabilized, Hannah was able to take coding and entrepreneurship classes at local colleges, which she said strengthened her to see her vision through.

The notOK app is Hannah’s first and Bug and Bee, LLC is her first company.

Watching his older sister suffer from a disorder made Charlie Lucas feel utterly helpless, he said.

Charlie couldn’t drive her to doctor appointments, he couldn’t make her better and he couldn’t even catch her when she fainted, he said.

But Charlie said he knew he could step in to help his sister when she told him about an idea for an app she’d had.

“I helped illustrate it out, so he would know what to do,” Hannah said of her brother. “He looked at my drawings and he coded it to tell the coders exactly what I wanted and how I wanted it to look.”

Charlie said his motivation for building the app came from watching his sister spiral into depression.

“I saw Hannah depressed, and she told me about her idea, and I started wire-framing it,” he said. “Making this app made her feel better and that made me feel better.”

Hannah pitched the app while taking a summer class on entrepreneurship at Georgia Tech. Professors there were so intrigued by the siblings’ creation that they connected the family with a development company in Savannah.

Over the course of five months, Hannah and Charlie said they worked side by side with the developers, often over Skype, to see their idea for the app turn into reality.

They also compiled research on mental health statistics to make the case that their app would find an audience.

Mental illness is defined by the National Institute of Mental Health (NIMH) as a mental, behavioral, or emotional disorder.

One in six U.S. adults lives with a mental illness, the institute reports.

Among adolescents, an estimated 49.5 percent between the ages 13 to 18 have a mental disorder, according to NIMH.

NotOK was launched in both iOS and Android versions. The app, which comes with a $2.99 monthly fee, allows users to press a button that sends a text message to up to five preselected contacts.

The text, along with a link to the user’s current GPS location, shows up on the contacts’ phones with the message, “Hey, I’m not OK. Please call me, text me, or come find me.”

“The reaction we’ve heard has been really positive, especially from parents and kids suffering with anxiety,” Hannah said. “Those kids don’t know the words to tell somebody.

“It definitely gave me a sense of comfort,” she said.

The app is available in iOS and Android versions at www.notokapp.com.