Yo messaging app used to alert Israelis about incoming rocket attacks

Local programmers used information provided by the Israeli military to create a 'Yo' username that sends notifications when rocket strikes are predicted

Yo's appeal is laughably ephemeral; it's a mayfly amongst apps

As the exchange of missiles between Israeli and Hamas intensifies, Israeli programmers have created an update for the Yo mobile app that alerts users when a rocket strike is imminent.

The Silicon Valley messaging app lets users exchange only a single word ("Yo”) and has been hailed as both “downright idiotic” and “unrivalled genius” after receiving more than $1 million in funding last month.

According to the Times of Israel, the new use for the app was created by local coders to complement their iOS and Android app Red Alert – a free download that use information from the Israeli Defense Force and Homefront Command to deliver the location and time of predicted rocket strikes.

Yo users in Israel and abroad can now add the user name REDALERTISRAEL on the app to receive push notifications on their smartphones whenever a rocket is inbound.

The notifications are an example of what fans of the app call “one-bit communication” - messages that have no ‘content’ apart from the fact of their existence. These rely on both the recipient and the sender knowing the context of the message – such as using a dropped call to let someone know you’re outside their house.

Israel has said it is preparing for a long-term offensive against Hamas militants in Palestine, with the country’s defence minister Moshe Yaalon saying: “We are preparing for a battle against Hamas which will not end within a few days.”