Gil Rabbi and Amit Sarusi, Co-Founder at Crowdr
Gil Rabbi and Amit Sarusi, Co-Founder at Crowdr (Image Credit Crowdr)

"Two highly talented" graduates of intelligence units in the Israeli army, established a technology and algorithm that enables communication between phones using sound waves independent of cellular reception or Internet connection.

600K Israelis who came to the "Festgial", the largest annual Israeli song and dance musical show for children, were surprised to be exposed to an innovative and surprising technological dimension when their mobile phones suddenly activated in the middle of the show. Their devices' flashlight turned on, while content related to the show projected on their screens, in real time and in full synchronization with the show’s pace. All in order to reach a special moment in the show where the children become an interactive part of it and actively affect it by voting what will happen in the next scene.

Anyone who has ever been to a concert or a show with thousands of other people, knows the feeling of frustration by cellular and WiFi networks collapse, and that the uploading story and photos from the show should be kept until the moment you get a little away from the hall. To overcome this obstacle, three Israeli experts have created an innovative and special technology based on sound waves only, without the need for an Internet connection (WiFi or Cellular) .

The technology is the result of the development of a young start-up (literally!), Crowdr, founded by Gil Rabbi. Rabbi is considered one of the global experts in creating digital products that improve engagement. His main specialty over the last decade has been making users stay longer in sites and apps, make them more involved in the content and allow website and app owners to get more user data.

Rabbi began his career in 2003, where during his military service he developed a system that engaged soldiers who came to enlist. The system improved the speed and time it takes for each new soldier to join the Israeli army. Immediately afterwards, he founded Rabbi Interactive, a technology agency based in Tel-Aviv

Over the past decade, Rabbi developed products that engaged over 5 million people every month, including products for Eurovision and the Rising Star TV format that enabled hundreds of thousands of viewers to participate in real-time.

Rabbi was chosen among the most influential people under 40 in the 40 under Forty list for 2018, and for one of the 100 most influential people in the digital fields in 2016, after the Amazon Web Services website published a review of the products he developed.

"We are actually working on sound technology that has been around for decades, but with the combination of the unique algorithm we have developed, it allows us to use it as innovatively as never seen before," explains Rabbi.

“We connect to the amplification systems in the show and transmit sound frequencies that human ears are unable to hear, but our app is capable of. And not only that, in order to retrieve the information back to us, we transfer the information between all the devices until it comes back to us. I have been developing real-time products and technologies for many years, and until now I have not found good solutions for crowded places where cellular reception problems are encountered. “

"The financial costs and technological complexity do not allow producers to connect an entire stadium to Internet communication - and that is where our technology comes into play." says Rabbi.

Together with Rabbi, The technology was created by two 18-year-old children who today are already serving in the best intelligence and computer units in the Israeli army.


Crowdr technology is divided into 2 fields, real-time technology and the unique algorithm that can transfer data to mobile devices in various configurations, regardless of internet communication.

For several years now, we have been developing and improving our real-time technology, which can operate and communicate with mobile phones without the need for cellular reception and without the need for additional electronic equipment other than the mobile devices of the people in the stadium or in the show grounds.

The knowledge and experience we have accumulated over the years has led us to solve various problems of synchronization in order to maximize the accuracy of all devices in the audience.

Thanks to the technology we have created, we are able to synchronize mobile devices of different people in one place in a precise way that enables us to transmit data to the audience, without having to rely on Wi-Fi, Bluetooth or Cellular service.

Crowdr website: