The “Yo” app was developed as a joke. Download the app, tap on a friend’s name, and they’d get a message from you saying “Yo.” It’s that simple. In fact, the app was created in eight hours and released on April Fools’ day just so people would know it was a gag.
But Yo has a new application that’s no laughing matter. Developers in the Middle East are using the app to warn Israelis of possible attacks from rocket fire; users following the handle “RedAlertIsrael” will get a “Yo” at the same time the country’s sirens go off.
One person’s gag app is apparently another’s survival tool.
More Must-Reads From TIME
- Can Birth Control Help Solve the World's Rat Problem?
- About That Devastating Tom-Shiv Scene in Succession's Premiere
- Why Humza Yousaf's Win Is 'Historic' for Scotland
- For Both Donald Trump and Alvin Bragg, the Central Park Jogger Case Was a Turning Point
- If Donald Trump Is Indicted, Here's What Would Happen Next in the Process
- Alison Roman Won't Sugarcoat It
- Why Not All Observant Muslims Fast During Ramadan
- It's Time to Say a Loving Goodbye to John Wick
- Who Should Be on the 2023 TIME100? Vote Now
- Column: Ozempic Exposed the Cracks in the Body Positivity Movement