Rising high school freshmen Julie Hess and Julia Kanaan spent their last day at Newtown Middle School, Monday, June 13, working after school to publish an app on the Google Play store.

The app that the girls shared on Friday, June 17, is designed to help toddlers learn about animals and animal sounds.

"Animal Sounds," a description for the app reads, "teaches children basic animal sounds. Animals listed on the app are a cat, sheep, dog, goat, pig, chicken, horse and cow." The app is free to download.

After hearing the sound an animal makes, users are instructed to "fling" the animal to dance with it. Once the user uses their finger to move the animal across the phone's screen, music begins to play and the animal "dances" along. After the user makes their way through all of the animals, a fact sheet shares more information.

"Cats are playful and like to drink milk," a voice says out loud. Another fact is, "Goats have horns and eat grass."

"I'm just so proud of them," said NMS computer integration teacher Rachel Smith.

The app began as a project in Ms Smith's class, and a couple of weeks after class ended, Ms Smith said the girls returned to ask if they could continue working on the project outside of class, and not for school credit. When she heard the request, Ms Smith said her heart jumped for joy.

"They did the app for their assignment, which is to build an app that can make a difference in the world," said Ms Smith, adding that she never expected students to want to work on a project after the class and project ended.

About a month before the school year ended, the girls, with inspiration from NMS Principal Thomas Einhorn, decided they wanted to publish the app.

When they started working on the app in class, Julia and Julie said fellow NMS student Ava Burns worked with them on the project. All three of the girls came up with the original idea for the app, according to Julia.

Julia also said she and Julie shared the app at the school's Celebration of the Arts during the evening of April 26.

"I think it is kind of cool," said Julia, about having a published app.

Since the girls first turned in the project, Julia said a few changes have been made.

"I thought there was something missing in the app, so I thought of this crazy idea of making the animals dance in the app," said Julia.

Inspiration for the project also came from Julia's younger cousins. One, Julia said, was taught animal sounds by memory, and Julia helped with the effort.

To create the app, the girls used Massachusetts Institute of Technology's (MIT) App Inventor. Learning how to create the app, Julia said, was fun.

"It brought out a lot of creativity and it was kind of cool, because I never thought I could do something like coding before," said Julia.

Julie said Ms Smith supported the girls and their project through to making it available on the Google Play store.

"We just had so much fun with it that with Ms Smith's help we just kept expanding it and expanding it," said Julie.

After completing the app, Julie said she feels inspired to do something like the project again.

"I feel like we could do a lot more," said Julie. She added later, "Ms Smith was great help. We really could not have gotten this far without her."