Gaithersburg teen Drew Mendelow developed an app to help people manage Type 1 diabetes. Photo by Liz Lynch

Diagnosed last September with Type 1 diabetes, then-eighth-grader Drew Mendelow wasted no time in developing an app to help him manage his illness. Kevin Xu, who graduated from Montgomery Blair High School this June, took the same approach when he was looking for a way to improve his participation in online classes.

The teens and a Kensington couple are among the Montgomery County residents who are using their talents to develop apps that solve problems and improve the lives of others. Here’s what they have created.


When Drew Mendelow was diagnosed at Children’s National Hospital in Washington, D.C., he was overwhelmed by the “math class” involved in treating his illness. “There was a lot of stuff to think about, like calculating insulin and carb counting,” says Drew, now 14, who lives in Gaithersburg. “[The nutritionist] kept mentioning that there wasn’t one app that would do everything.”

The day he arrived home from the hospital, Drew used his modest coding background to begin work on T1D1, a free app designed to help people manage Type 1 diabetes. The app, which Drew designed using the online app builder Thunkable, calculates the correct dose of insulin based on personal specifications, and is able to log the figures so they can be sent to medical providers. It also has a food library where users can list the amount of carbs in frequently used recipes.

Drew coordinated with the doctors at Children’s to provide guidance and suggestions on the app, which is available in the App Store and on Google Play. It has been downloaded more than 24,000 times in more than 50 countries since it was launched on Oct. 31. Dr. Brynn Marks, the endocrinologist who diagnosed Drew, says her team recommends the app to patients. Drew used it until he got an insulin pump in December that calculates doses and administers medication, but he still uses the food library.

A ninth grader at Quince Orchard High School, Drew is working on translating the app into Spanish and Chinese, and he has added a measurement unit for blood sugar that’s commonly used outside the U.S. “I’m really just hoping this app reaches as many people that need it as possible from anywhere—give them one less thing to worry about,” he says.



After the pandemic forced classrooms to shift online in the spring of 2020, Kevin Xu, then a junior in Blair’s science, mathematics and computer science magnet program, noticed some logistical problems in his organic chemistry class. “For classes like math or chemistry, you really need to draw stuff,” says the 18-year-old Bethesda resident. “Unless you have a drawing pad, your mouse drawings—they’re not the most legible.”

Kevin and Leon Si, a fellow teenage computer coder in Canada, developed Tabulo—a free online whiteboard app that allows users to create drawings on their mobile devices that can be synchronized in real time to a computer. Users can find the app on the website and then create a “room” that can be joined from a smartphone through a link or a QR code, a two-dimensional barcode. Teachers and students can view or edit the virtual whiteboard and annotate PowerPoint slides, zoom in to make more detailed drawings, or download what’s on the board as images.

Kevin created a prototype in about a week in April 2020, inspired by drawing pads he used in a digital art class at Blair. He later turned to Amazon Web Services for help in developing the app while Leon focused on coding. The app became available in early August 2020 and was used by students and teachers in some of Kevin’s classes during his senior year. As of late April, it had almost 100 registered users.


In December, Kevin and Leon won U.S. Rep. Jamie Raskin’s 2020 Congressional App Challenge, which encourages middle and high school students to develop coding and computer science skills. Winning apps are displayed on the U.S. House of Representatives website and in a U.S. Capitol exhibit. “Winning the app [contest] is great, but I also want to actually help teachers around the world,” Kevin says.

Virtues Cards

When Dara Feldman learned in 2005 about The Virtues Project, an initiative to encourage people to incorporate virtues into their lives, she started carrying its packs of “virtue cards.” The cards include a description of a quality such as courage or tolerance, an applicable quote from a well-known person such as Mother Teresa, and ways to practice the trait.

Feldman, a former teacher and instructional technology specialist for Montgomery County Public Schools, often ended up with incomplete decks after giving away cards. So in 2008 she helped develop the first generation of Virtues Cards, an app that digitized the cards. Feldman and her husband, Dave, who live in North Bethesda, launched a redesigned version of the app in February 2020 under their new nonprofit, Virtues Matter, which they founded in 2019.


After opening the free app, users shake their phones to receive a randomly chosen virtue card or scroll to find a specific virtue card in one of its decks, which include reflection, resilience, family, education and character. The app, available on Google Play and in the App Store, comes with a starter deck; additional decks cost up to $4.99. Users can share the cards through texts, email or social media. The app also includes a journal, and it allows users to set up daily reminders to pick a card.

“Our whole reason for creating this app was to have virtues go viral,” says Dara Feldman, 58, a former director of education for The Virtues Project. “[For people] to be able to live their highest version of themselves and to see that and recognize it in others.”