JERUSALEM (AFP) - The barrage of rocket fire from Gaza has not just triggered a rush for shelters, but has also sent Israelis scrambling to download applications to help cope with the frequent alerts.

With nearly half a million downloads, the "Red Alert" smart phone application has become an everyday essential for Israelis since the July 8 start of Israel's military operation to stop Palestinian rocket fire brought a paradoxically sharp increase in attacks.

Since then, militants have fired more than 1,200 rockets and mortar rounds at Israel, and Israel has bombed more than 1,750 targets inside the Gaza Strip, the army said on Wednesday.

One Israeli has been killed and four seriously wounded.

In Gaza, more than 220 Palestinians have been killed, according to medics.

Red Alert is meant to complement other means of warning, alongside the air raid sirens in every Israeli city, town and village and the real time alerts broadcast on national radio channels.

It gives people who are not close to a radio, or who are unable to hear a siren, an extra warning and allows people in one location to know what is happening to friends and family elsewhere in the country.

But Sophie Taieb, 37, manager of a web community in Tel Aviv, says that coming on top of the mainstream warnings, the app just adds to the tension.

"When it sounds to signal an alert in Tel Aviv, I'm already on the stairs trying to run to shelter," she says, having already heard the local sirens.

"I hesitate to have it turned on because it makes me terribly anxious." Israeli application "Yo!", which raised a million dollars in startup money at the end of June, started out as "a Joke app" the Times Of Israel news website said.

It has the cryptic function of sending the word "Yo!" which the recipient is meant to know means the caller is perhaps waiting at a rendezvous, outside in the car or maybe wants to be called back.

Israelis have customised it to pass on warnings from other sources, for example by sending the message "Yo!AlertJerusalem."

- Anti-snatch app -

Another application "Secure Spaces" offers an interactive Google map of the nearest public shelters, which can often be concrete blocks at the side of the street or an underground car park.

Kidnap rescue app "NowForce SOS" was downloaded nearly 100,000 times after last month's abduction and murder of three young Israelis hitchhiking in the occupied West Bank, allegedly by Palestinian militants.

Following the discovery of their bodies in a shallow grave, a Palestinian teenager was kidnapped and burned to death in what police say was a revenge attack by Jewish extremists.

Launched six years ago in Hebrew and English, an Arabic-language version is currently in the works.

"The user, who must register in advance on our website, opens the application and clicks on the SOS button," developer Dov Maisel told AFP.

"His location is plotted by GPS and in less than three minutes a rescue team can be on the scene." These applications have been developed by civilians and Israelis are likely to ask what the authorities are doing in the field in a country known for its hi-tech startups and slick IT products.

Asked about the development of military applications to help people in times of war, an army spokesman told AFP without elaborating that "the project is in progress."