( CNN ) -- Israelis looking to know when to take cover are turning to their smartphones to get real-time notifications after Hamas fires rockets from Gaza . The Red Alert app co-created by Ari Sprung , an Israeli software developer born in the United States , has become increasingly popular as the conflict escalates . While the country 's Iron Dome missile defense system intercepts most rockets , some do get through . As a live interview with Sprung and CNN 's Brooke Baldwin began Wednesday , both phones -- one in Jerusalem , the other in Atlanta -- sounded in real time as rockets were fired toward the Israeli cities of Ashkelon and Ashdod . Sprung partnered with another Israeli software developer , Kobi Snir , after the 2012 escalated conflict between Israel and Hamas . `` We knew this would happen again , so we wanted to make sure we had an app ready to alert Israelis for the next conflict , '' Sprung told CNN . Red Alert receives notifications when rockets are being launched from Gaza , and automatically sends out a push notification to users via the downloaded app . Their phone will play an emergency tone and display the name of the targeted community . The free app is available on iOS and Android devices . Sprung works full time at a software development company , and tends to Red Alert in his free time . The servers are hosted for free by ShartimIsrael , an Israeli web hosting company , he says . For security reasons , the developers wo n't say how they get their notifications of rockets being launched . But they tell CNN the time delay is less than a second of when the audible sirens are sounded . At one point Tuesday , a rocket was being launched every six minutes . Life in Gaza : Search for safety , or wait for destiny . Once the app is downloaded , users can select which Israeli cities for which they want to get alerts . Most users select `` all areas . '' Israeli officials and the Israel Defense Forces have publicly supported the app , and encourage people to download it . Before the latest Gaza operation , there were 60,000 Android users and 80,000 iPhone users , all in Israel . Today , Sprung tells CNN , there are approximately 290,000 Android users and 300,000 iPhone users worldwide , based on information from Apple 's iTunes store and Google Play store . Of the 300,000 iPhone users , 250,000 are from Israel and 50,000 are in the United States and other countries . The Android app is n't available outside of Israel due to limited server space ; instead users with an Android device wanting to receive updates can do so through the `` Yo '' app . Trapped in war : 'This is tyranny ' Gilad Harazy , an Israeli native studying in the United States , has family back in Israel , and keeps up with developments through the app . `` I want to know when it hits close by where my parents live , '' he says . `` I know if it hits they wo n't be able to contact me immediately , so I want to be able to know to get in touch with them to make sure they 're OK. '' Harazy 's family lives in the town of Nir-Banim , roughly 20 miles from the Israel-Gaza border . His parents have approximately one minute to seek shelter once the alerts go off , he says . The time it takes for Israeli 's to seek shelter varies , based on how far they are from the Gaza border . `` It 's great to be able to know on the spot when the alarm goes off , '' Harazy tells CNN . `` In Israel , you might be in a closed room not near the sirens , so this new app allows you to know when something 's going on . Although I 'm happy to be able to know when rockets fall , it 's really sad to know we need something like this . '' Racing toward danger : War-scarred Gaza medical crews also in harm 's way . Follow Noah Gray on Twitter @ NoahGrayCNN .
Israeli developers create Red Alert smartphone app . It notifies users when Hamas launches rocket from Gaza . People outside the region use it to follow developments in loved ones ' cities .