After the election, Natalia Margolis felt helpless. Like the overwhelming majority of her fellow San Franciscans, Margolis had vehemently opposed Donald Trump's candidacy. His victory left her wondering what she could possibly do to defend people against what she believed would be at least four years of anti-immigrant policy sweeping the country.

So Margolis, an engineer for the digital agency Huge, went to a meet-up group for women and Latinos in tech that focused on civic action. There she met Adrian Reyna. Reyna's parents, both undocumented, brought him and his two sisters to the United States from Mexico when he was 12 years old. Though he and his siblings enjoyed protection as so-called DREAMers under President Obama, the whole family now lives in fear they could face deportation. That wouldn't just be heartbreaking and terrifying, he said. It would be a logistical nightmare.

Getting picked up by immigration agents means getting wrenched from your daily life, often with no warning. You have no time to find someone to pick up your kids, alert your boss, pay your bills, or delegate a million other daily tasks. Those responsibilities don't disappear just because you're in detention. Reyna wished a way existed to take at least that stress off the shoulders of people enduring the most stressful moments of their lives.

"There’s never going to be a panic button for when ICE comes to the door," Reyna lamented at the meet up. Margolis thought maybe there could be.

She took the idea back to her team at Huge, which happened to be hosting a hackathon focused on solving big social issues. Just 24 hours later, Notifica, an app debuting this week at South by Southwest, was up and running.

The app allows people to select contacts they would want to notify in case of emergency and pre-load personalized messages to each recipient. A message to your lawyer would read differently, say, than a message to your spouse. Once you've loaded the alerts, no one else can read them. A PIN protects them in case the phone is lost or stolen, and for most users, the hope is they never have to use the app again. For those who do, a single click deploys all the messages by text in less than two seconds. Huge has also created a phone hotline for people who don't have a phone in reach but who may be able to make a phone call later on.

Huge has partnered with United We Dream, where Reyna is director of membership and tech strategies, to disseminate the app to families in states like Texas, Florida, and New Mexico—anywhere with large immigrant communities.

No app can do away with what amounts to an existential threat for many families.

Until now, social media has served as the primary tool for people looking to spread the word about loved ones being deported. But such public platforms are far from secure, says Reyna. "We don't know in what way the government will be using information people interact with or put on social media," he says. "We don't want to put our community at risk."

President Trump's executive order on immigration effectively does away with the rules dictating who is and isn't a priority for deportation. Now, the order could apply to anyone who has ever defrauded the government, been suspected of a crime, or who a law enforcement officer judges to be a threat. That leaves lots of room for discretion for immigration agents and police, and little to no security for the roughly 11 million undocumented immigrants living in this country.

Notifica can give families a sense of security in a moment they otherwise might feel like they have none. But no app can do away with what amounts to an existential threat for many families. Technology alone can only do so much. But a button to press is better than nothing at all.