|Initial release||April 1, 2014|
|Operating system||iOS, Android, Windows Phone|
Yo is a social mobile application for iOS, Android, and Windows Phone. Initially, the application's only function was to send the user's friends the word "yo" as a text and audio notification, but it has since been updated to enable users to attach links and location to their "Yo"s.
Yo was created by Israeli developer Or Arbel in eight hours, being launched on April Fools' Day 2014 for Android and iOS. Originally chief technology officer of stock trading platform Stox, Arbel quit his job and has since begun working on the app full-time. The app has received USD$1 million in investment from a group of investors led by Moshe Hogeg, CEO of Mobli, who had originally asked Arbel to design a single-button app to call his assistant. In July 2014 the app was also released for Windows Phone. The app was valued at between $5 and $10 million in July 2014 and received a further $1.5 million in funding. Website IFTTT included Yo as an option for their service in July 2014.
Arbel stated interest in expanding the app to include more functionality, including a possible feature which could be used by bloggers to send their followers a 'yo' with a link to the blog attached whenever they post an update; the feature has since been implemented. The app's first content update was released in August 2014, adding extra functionality to it, including the ability to send web links and hashtags, and creating user profiles.
On 20 June 2014, Isaiah Turner hacked the app, allowing him to retrieve any user's phone number and spam/spoof 'Yo's to any user. After the exploit was fixed, Arbel hired him to work for the company.
In October 2014, the app introduced functionality to enable users to send their location to other users by simply double tapping their username.
In June 2015, Yo released the second version of their app with a number of new features. The user interface was updated to allow users to send photos or their location within 1 swipe and a tap from the home screen. The new version also enabled users to collect their friends in to groups so that they could "Yo" a number of people with 1 tap.
Since its release, Yo has been downloaded over 3 million times and over 100 million 'Yo's were sent. Joachim Fels, an economist at Morgan Stanley, expressed interest in the app due to its simplicity. The app reached number 3 in the iOS App Store, but has since fluctuated in ranking.
A number of apps inspired by Yo have been released, including one which sends the word 'Hodor', and an Indian-made app which sends the word 'aiyo'. The app has also been adapted to warn Israeli citizens of missile strikes. An app called Lo was partly inspired by Yo, sending only a user's location. In July 2014 some of the copies and parodies received copyright complaints from Yo, with Or Arbel saying "Yo has spawned many clones... some of them are a complete replication of the Yo app... Improving upon our concept is welcomed, copying us bit-by-bit isn’t."
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- Fiegerman, Seth. "Yo App Now Does Much More Than Let You Say 'Yo'". Retrieved 16 October 2016.
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- Lomas, Natasha (12 August 2014). "Yo, The One-Word Messaging App, Updates So It's Not Quite So Absurdly Simple Anymore". TechCrunch. Retrieved 23 August 2014.
- Claman, Liz (24 June 2014). "Yo CEO hires hacker". Fox Business. Retrieved 20 May 2017.
- Hern, Alex (2 July 2014). "Yo founder apologises for hack – and hires one of his hackers". The Guardian. Retrieved 2 July 2014.
- Fiegerman, Seth. "Yo App Users Have Sent More Than 100 Million Yos". Retrieved 16 October 2016.
- Aglionby, John (24 June 2014). "Yo app passes 1m downloads". Financial Times. Retrieved 24 June 2014.
- Weisenthal, Joe (23 June 2014). "We Officially Have Our First Wall Street Economist Talking About The 'Yo' App". Business Insider. Retrieved 23 June 2014.
- Tweedie, Steven (28 June 2014). "The Rise, Falter, And Future Of Yo". Business Insider. Retrieved 2 July 2014.
- Larson, Jared (1 July 2014). "The Yo, Hodor App Provides a New Outlet for Your Inner Hodor". IGN. Retrieved 2 July 2014.
- Madhok, Diksha (25 June 2014). "India has a fitting response to Yo, the dumbest app ever". Quartz. Retrieved 2 July 2014.
- "Yo app warns Israeli citizens of missile strikes". BBC News. 10 July 2014.
- Cosco, Joey (20 August 2014). "Someone Made An App Like Yo, But It Shares Your Location Instead". Business Insider. Retrieved 23 August 2014.
- Perez, Sarah (31 July 2014). "Yo Is Trying To Get Parody App YOLO & Others Pulled From The App Store". TechCrunch. Retrieved 23 August 2014.