Imagine you’re at a pro-democracy rally in a repressive country when the police arrive, clubs swinging. You reach for your phone to document the brutality, but you’re worried the authorities will detain you and erase the evidence, or worse: use the fact that you were shooting video to justify additional harassment. How can you capture what’s happening without endangering yourself? There’s an app for that.

Raphael Mimoun, F15, launched the free Whistler app for Android phones in February, just in time to monitor contentious elections in eastern Europe. It hides in a user’s app list and encrypts collected multimedia in a concealed gallery, thereby protecting activists as well as the data they gather. Whistler also embeds metadata to make reports more verifiable.

“We built it from the ground up with security in mind,” said Mimoun, executive director of Build A Movement (BAM), a Washington, D.C.–based nonprofit that supports democracy advocates around the world. The idea for the app came from Mimoun’s conversations with Srdja Popovic, executive director of the Centre for Applied Nonviolent Action and Strategies (CANVAS), a sister organization to BAM that also works with leaders of nonviolent resistance movements. Indigenous groups, citizen journalists, and other activists have all expressed interest in Whistler.

In response to reports of arrests and disappearances in the field, the app has a “panic” button that alerts trusted contacts that a user is in danger and shares the user’s location. It also erases sensitive information.

It took Mimoun and a team of part-time developers two years to create Whistler with $150,000 from supporters, including CANVAS, which is chaired by Serbian businessman Slobodan Djinovic, F06. With funding from Jigsaw, a Google incubator, Mimoun hired a German firm to test the app’s code for vulnerabilities. If BAM receives additional money, an iPhone version may be next.

“An app is not going to change the world,” Mimoun said. “But it can protect people and document injustice, and that’s going to help those people change the world.”

Heather Stephenson

Heather Stephenson, senior writer at Tufts and editor of Fletcher Magazine, can be reached at