Cheaper calls between France and Mali: this is what motivated Mamadou Gouro Sidibé to return to his home country to develop an application. But nothing went as planned.

"My name is Mamadou Gouro Sidibé. I was born in Mali. I first became a network engineer in Russia. Then I came to France where I get a PhD in computer sciences at the University of Versailles, and I worked for more than ten years for big research and development projects funded by the European Commission in the field of computers, networks and multimedia.

That's when I took the plunge: trying to create a Malian Viber. As I had family here in France and in Africa, I had a strong need to call. And it was expensive! Viber and WhatsApp made it cheaper, but it didn't always work very well.

So I wanted to make one that would work very well in my country. I went to Mali to do this Viber there. And difficulties began to appear. Every time I had a good idea, Viber or WhatsApp would come up with the same thing while I was doing tests.

Until one day, at the corner supermarket, someone handed me a phone. He told me: "Boss! I have a message on my phone in French and I can't read it." I know that in Mali there are many people who cannot read and write. But I didn't think he was one of them.

So I thought: "Gee, I'm running after Viber when he doesn't even understand." We must move towards something that would start from local realities, for simple people. So I began making voice guides: I made people listen in the local language.

I was alone with a lady who was cleaning up. I handed her the phone to create her profile, and she said: "I don't know how to put my profile on." She couldn't write her name. So I thought that I had to find something else for all these people, and they are the majority of the 1.2 billion people in Africa, totally left out."