WhatsApp with a super new feature for group communication
WhatsApp Messenger is a proprietary, cross-platform, encrypted instant messaging client for smartphones.  It uses the Internet to send text messages, documents, images, video, user location and audio messages   to other users using standard mobile cellular numbers.
As of February 2016 Had A WhatsApp user base of one billion,   Making it the Most popular messaging application.  
WhatsApp Inc., based in Mountain View, California, United States, Was Acquired by Facebook Inc. on February 19, 2014, for approximately US $ 19.3 billion.
WhatsApp Inc., Was Founded in 2009 by Brian Acton and Jan Koum, Both Former Employees of Yahoo !. After Koum and Acton left Yahoo! in September 2007, the duo traveled to South America as a break from work.  At one point broke the APPLIED for jobs at Facebook Were Rejected soft.  For the rest of the Following years Koum relied on his $ 400,000 savings from Yahoo !. In January, 2009, after Purchasing an iPhone and realizing That the seven-month-old App Store Was about to spawn a whole new industry of apps, he Started visiting His friend Alex Fishman in West San Jose Where Would Discuss the three “… having statuses next to individual names of the people, “But this wasnt Possible without an iPhone developer, so Fishman Introduced to Igor Solomennikov Koum, a developer in Russia That he hadd found on RentACoder.com. Koum almost immediately chose the name “WhatsApp” Because it sounded like “what’s up”, and a week later on his birthday, on February 24, 2009 he incorporated WhatsApp Inc. in California. Howevera, WhatsApp early Kept crashing or getting stuck and at a Particular Point, Koum felt like giving up and looking for a new job, Acton qual upon Encouraged Him to wait for a “few more months”. 
In June 2009 Launched Apple push notifications, letting developers ping users When They Were not using an app. That Koum updated WhatsApp so Each time the user changed their statuses, It would ping everyone in the user’s network.  WhatsApp 2.0 was released with a messaging component and the active users suddenly swelled to 250,000. Visited Koum Acton, Who Was the while Managing unemployed still another startup and Decided to join the company.  In October Acton persuaded five ex-Yahoo! friends to invest $ 250,000 in seed funding,, and as a Result Was Granted co-founder status and a stake. Officially he joined on November 1.  After months at beta stage, the application Eventually Launched in November 2009 Exclusively on the App Store for the iPhone. Koum said WHO hired an old friend Lived in Los Angeles, Chris Peiffer, to make the BlackBerry version, Which arrived two months later. 
Was WhatsApp switched from a free to paid service to Avoid Growing too fast, Mainly Because the primary cost verification Was sending texts to users. In December 2009 Was WhatsApp for the iPhone updated to item photos. By early 2011 WhatsApp Was in the top 20 of all apps in Apple’s U.S. App Store. 
In April 2011, Sequoia Capital Was the only venture investor in WhatsApp and paid approximately $ 8 million for more than 15 Percent of the company in 2011 on top of developer’s $ 250,000 seed funding,, after months of Negotiation with Sequoia partner Jim Goetz.  [ 20] 
By February 2013, WhatsApp’s user base hadd swollen to about 200 million active users and its staff to 50. Sequoia invested another $ 50 million, valuing WhatsApp at $ 1.5 billion. 
In a December 2013 blog post, WhatsApp That claimed 400 million active users Each month use the service.  As of April 22, 2014, WhatsApp hadd over 500 million monthly active users, 700 million photos and 100 million videos daily Were being shared, and the messaging system Was handling more than 10 billion messages Each Day.  On August 24, 2014, Koum Announced on his Twitter account WhatsApp That hadd over 600 million active users Worldwide. That point WhatsApp Was At adding about 25 million new users Every month, or 833 000 active users per day.   With 65 million active users Representing 10% of the total users Worldwide, India has the Largest number of Consumers. 
Facebook era (2014-present) 
On February 19, 2014, months after a venture capital financing round at a $ 1.5 billion valuation,  I Was Announced Acquiring Facebook WhatsApp for US $ 19 billion, its Largest acquisition to date.  At the time, the acquisition Largest Was the purchase of a venture-backed company in history. Sequoia Capital Received an approximate 50x Its initial return on Investment.  Facebook, Which Was Advised by Allen & Co., paid $ 4 billion in cash, $ 12 billion in Facebook shares, and an additional $ 3 billion in restricted stock units Granted to WhatsApp’s Founders (Advised by Morgan Stanley), Koum and Acton.  Employee stock Was scheduled to vest over four years subsequent to closing.  The transaction Largest Was the purchase of a company backed by venture capitalists to date.  Days after the announcement, WhatsApp users Experienced a loss of service, leading to anger across social media. 
The acquisition considerabl caused a number of users to move, or try out other message services as well. Telegram claimed to have seen 8 million downloads of Its app additional.  Line claimed to have seen 2 million new users for Its service. 
At a keynote presentation at the Mobile World Congress in Barcelona in February 2014, Facebook CEO Mark Zuckerberg Said That Facebook’s acquisition of WhatsApp Was Closely related to the Internet.org vision.   According to a TechCrunch article, Zuckerberg’s vision for Internet.org Was as Follows: “The idea, He Said, is to Develop a group of basic online services That Would be free of charge to use – ‘a 911 for the internet.” These Could Be a social networking service like Facebook, a messaging service, maybe search and other things like weather. Providing a bundle of These free of charge to users Will work like a gateway drug of sorts – users WHO May Be Able to Afford data services and phones These days just do not see the point of why They would pay for Those data services. this would give context for why tell Some They are Important, and say That will lead to Paying for more services like this – or so the hope goes. “
On May 9, 2014, the government of Iran Announced That it hadd Proposed to block the access to WhatsApp to Iranian Residents service. “The reason for this is the assumption of WhatsApp by the Facebook founder Mark Zuckerberg, Who is an American Zionist,” said Abdolsamad Khorramabadi, head of the country’s Committee on Internet Crimes. Iranian president Hassan Rouhani Subsequently issued an order to the Ministry of ICT to stop filtering WhatsApp.  
Just three days after WhatsApp Announcing That hadd been purchased by Facebook, Koum Said They Were working to Introduce voice calls in the coming months. Also He advanced That WOULD BE new mobile phones sold in Germany with the brand WhatsApp, nor Their main goal Was to swear in all smartphones. 
In August 2014 Was the WhatsApp messaging app Most popular globally, with more than 600 million active users.  By early January 2015, WhatsApp hadd 700 million monthly active users with over 30 billion messages being sent Every Day.  In April 2015, Forbes That the predicted between 2012 and 2018 the telecommunications industry will lose a combined total of $ 386 billion Because of OTT services like WhatsApp and Skype.  That month, WhatsApp hadd over 800 million active users.   By September 2015, the user base hadd grown to 900 million,  and by February 2016 it hadd grown to one billion. 
As of November 30, 2015, the Android client for WhatsApp Started Making links to another messenger called Telegram unclickable and uncopyable.    This is an active block, as confirmed by multiple sources, Rather than a bug,  and the Android source code recognises Telegram Which URLs has been Identified.  URLs with “telegram” domain name as TARGETED are actively and explicitly – the word ‘telegram’ Appears in the code.  This functioning Risks being considered anti-competitive,    and has not been Explained by WhatsApp.
On January 18, 2016 WhatsApp’s founder in January Koum Announced That the service Would no longer charge of developer users a $ 1 annual subscription fee in an Effort to remove a barrier faced by Some users WHO do not have a credit card to pay for the service. [ 46]  He Explained That the app Also wouldn’t display any third party advertisement and Instead Would Bring New Features Such as the Ability to Communicate with Business Organizations.  
By June 2016, more than 100 million voice calls are made per day on WhatsApp according to a post on the company’s blog.
After months at beta stage, the application Eventually Launched in November 2009 Exclusively on the App Store for the iPhone. In January 2010, support for BlackBerry smartphones Was added, and subsequently for Symbian OS in May 2010 and for Android OS in August 2010. In August 2011 a beta for Nokia’s non-smartphone OS Series 40 Was added. A month later for Windows Phone support Was added, Followed by BlackBerry 10 in March 2013.  In April 2015, support for Samsung’s Tizen OS Was added.  An unofficial port has been released for the MeeGo-based Nokia N9 called Wazapp,  as well as a port for the Maemo-based Nokia N900 called Yappari. 
The oldest device Capable of running WhatsApp is the Symbian-based Nokia N95 released in March 2007.
In August 2014, WhatsApp released an update to Its Android app, adding support for Android Wear smartwatches. 
In 2014 an unofficial open source plug-in called WhatsApp purple was released for Pidgin, Implementing Its XMPP and Making It Possible to use WhatsApp on a Windows or Linux PC.  [third-party source needed] WhatsApp responded by automatically blocking That phone numbers connected to WhatsApp using this plug-in. 
On January 21, 2015, WhatsApp WhatsApp Launched Web, a web client Which Can Be used through a web browser by syncing with the mobile device’s connection. 
On February 26, 2016, WhatsApp Announced They Would Cease support for BlackBerry (BlackBerry Including 10), Series 40 and Symbian, as well as Some older versions of Android, Windows Phone and iOS, by the end of 2016. 
WhatsApp Web 
WhatsApp Was Officially made available for PCs through a web client, under the name WhatsApp Web, in late January 2015 through an announcement made by Koum on his Facebook page: “Our web client is simply an extension of your phone, the web browser mirrors conversations and messages from your mobile device-this Means all of your messages on your phone still live. ” The WhatsApp user’s handset must still swear connected to the Internet application for the browser to function. All major desktop browsers are supported except for Microsoft Internet Explorer. WhatsApp Web’s user interface is based on the default Android one.
As of January 21, 2015, the desktop version Was available only to Android, BlackBerry and Windows Phone users. Later on, it Also added support for iOS, Nokia Series 40 and Nokia S60 (Symbian).  
An unofficial derivative called WhatsAppTime has been Developer, Which is a standard Win32 application for PCs and supports notifications through the Windows notification area.  Similar There are solutions for Mac OS X, Such as the open-source chitchat    and multiple wrappers available in the App Store. [Citation needed]
Windows and Mac 
On May 10, 2016 Was Introduced the messaging service for Both Windows and Mac operating systems. Similar to the WhatsApp Web format, the app, Which Will Be synced with a user’s mobile device, is available for download on the website. It supports OS versions of Windows 8 and Mac OS 10.9 and higher.  
WhatsApp uses a customized version of the open standard Extensible Messaging and Presence Protocol (XMPP).  Upon installation, it Creates a user account using one’s phone number as the username (Jabber ID: @ s.whatsapp.net).
WhatsApp software automatically compares all the phone numbers from the device’s address book With its central database of WhatsApp users to automatically add contacts to the user’s WhatsApp contact list. Previously the Android and Nokia Series 40 versions used an MD5-hashed, reversed-version of the phone’s IMEI or password,  While the iOS version used the phone’s Wi-Fi MAC address Instead of IMEI.   A 2012 update now generates a random password on the server side. 
Some devices Dual SIM compatible with the EU may not WhatsApp, though there are Some workarounds for this. 
In January 2015, WhatsApp Introduced a voice calling feature; WhatsApp this helped to attract a Completely Different Population segment of the user. 
Multimedia messages are sent by uploading the image, audio or video to swear sent to an HTTP server and said sending a link to the content Along with Its Base64 encoded thumbnail (if applicable). 
WhatsApp Follows a ‘store and forward’ mechanism for Exchanging messages between two users. When a user sends a message, it first travels to the server WhatsApp Where it is stored. Then the server requests the receiver repeatedly acknowledge receipt of the message. As soon as the message is acknowledged, the server drops the message; it is no longer available in the database of the server. WhatsApp Keeps the message server only for 30 days in Its database When it is not delivered (When the receiver is not active on WhatsApp for 30 days).