In a small village four hours outside of Bolivia's capital, La Paz, there exists a community with no currency and little access to technology. And yet, the pathways are littered with QR codes. They were put there by a group of ten Bolivian teenage girls who wanted to make the hours-long walk to school a little more fun for local children. The game works by encouraging bypassers to scan the barcodes with their smartphones – the one common technology in the area. The offline app then presents them with a multiple-choice quiz on a range of educational subjects, such as computer programming, history, English and Aymara — the village's native language. For every correct answer, players receive a point, which they can use to compete against their friends. For the girls who built the app – "Learn by Sarana" (Sarana translates to walking in Aymaran) – it was their first real opportunity to learn about technology, let alone programming.

Founders of QR code app Learn by Sarana Iridescent

Not withstanding their impressive accomplishment, they are far from unique. They're just a handful of the billions of women and girls who have been hindered from developing STEM — science, technology, engineering and math — skills as a result of gender, geography and finances. They are also among more than 110,000 girls who, over the past 13 years, have found a new route into STEM through a series of free programs run by nonprofit start-up, Iridescent.

Opening up STEM to women

Iridescent was founded in 2006 by Tara Chklovski, an Indian native who was stunned into action shortly after moving to the U.S. "When I arrived, I was struck by the lack of diversity in STEM in the U.S.," Chklovski, who had moved to the States to complete her aerospace engineering PhD, told CNBC Make It.

Tara Chklovski, founder and CEO of Iridescent. Iridescent

I expected much more parity in a first world country. Tara Chklovski Founder and CEO of Iridescent

"I expected much more parity in a first-world country," she continued, referring to both STEM careers and boardrooms. In the last 13 years, Chklovski has made it her mission to rectify that imbalance, giving up her studies to develop Iridescent's training programs for students — especially girls and mothers — particularly in emerging countries. For that, she has enlisted volunteers and major tech companies, such as Apple, Google, IBM, Salesforce and Intel, who she said are increasingly seeing the value of employee volunteer schemes.

For companies, the scheme has the double benefit of allowing staff to give back and also creating recruiting opportunities among the students further down the line, said Chklovski. "Collaborating with organizations like Iridescent provides employees with opportunities to connect with important social causes they care about, working together to create lasting impact," Intel Foundation's deputy director, Gabriela A. Gonzalez told CNBC Make It. "By partnering with Iridescent in programs like Technovation and the AI Family Challenge, we know that we are contributing to the development of a qualified, diverse STEM workforce who will be the innovators and leaders of tomorrow," added Hina Baloch, STEM education lead at General Motors, another of Iridescent's partners.

Progress for the future

The program works by targeting school-age girls who would not otherwise have good access to STEM education classes. During the year-long course, the students receive tech training and are encouraged to develop solutions to issues impacting their local communities. In the past, those projects have culminated in apps to cut ticket queues, help phone recycling and even end Female Genital Mutilation. The classes take place outside school hours, which means families, and specifically mothers, are able to attend too. That's all part of what Chklovski called her "methodical" strategy to also help mothers — many of whom left the workforce when they had their first child — to upskill and return to work.