whatsapp Messenger information

WhatsApp Messenger is a freeware and cross-platform instant messaging service for smartphones.It uses the Internet to make voice calls, one to one video calls; send text messages, images, GIF, videos, documents, user location, audio files, phone contacts and voice notes to other users using standard cellular mobile numbers. All data are end-to-end encrypted. It also incorporates a feature called Status, which allows users to upload photos and videos to a 24-hours-lifetime feed that, by default, are visible to all contacts, similar to Snapchat, Facebook and Instagram Stories. The client was created by WhatsApp Inc., based in Mountain View, California, which was acquired by Facebook in February 2014 for approximately US$19.3 billion.By February 2016, WhatsApp had a user base of over one billion,making it the most popular messaging application at the time.

History

Further information: Timeline of WhatsApp
2009–2014
WhatsApp, was incorporated 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.[18] At one point they applied for jobs at Facebook but were rejected. 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 App Store would soon create an industry of apps, Koum started visiting his friend Alex Fishman in West San Jose where the three would discuss ".... having statuses next to individual names of the people", but this was not possible without an iPhone developer. Fishman found a Russian developer on RentACoder.com, Igor Solomennikov, and introduced him to Koum. Koum named the app "WhatsApp" to sound like "what's up". On February 24, 2009, he incorporated WhatsApp Inc. in California. However, because early versions of WhatsApp often crashed or got stuck at a particular point, Koum felt like giving up and looking for a new job, upon which Acton encouraged him to wait for a "few more months".
In June 2009, Apple launched push notifications, allowing users to be pinged when they were not using an app. Koum changed WhatsApp so that when a user's status is changed, everyone in the user's network would be notified. WhatsApp 2.0 was released with a messaging component and the number of active users suddenly increased to 250,000. Acton was still unemployed and managing another startup, and he decided to join the company.In October 2009, Acton persuaded five former friends in Yahoo! to invest $250,000 in seed funding, and Acton became a co-founder and was given a stake. He officially joined on November 1.[18] After months at beta stage, the application eventually launched in November 2009 exclusively on the App Store for the iPhone. Koum then hired a friend who lived in Los Angeles, Chris Peiffer, to develop the BlackBerry version, which arrived two months later.
WhatsApp was switched from a free to paid service to avoid growing too fast, mainly because the primary cost was sending verification texts to users. In December 2009, the ability to send photos was added to WhatsApp for the iPhone. By early 2011, WhatsApp was one of the top 20 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, after months of negotiation with Sequoia partner Jim Goetz.
By February 2013, WhatsApp had about 200 million active users and 50 staff members. Sequoia invested another $50 million, and WhatsApp was valued at $1.5 billion.
In a December 2013 blog post, WhatsApp claimed that 400 million active users use the service each month.[22] As of April 22, 2014, WhatsApp had over 500 million monthly active users, 700 million photos and 100 million videos were being shared daily, and the messaging system was handling more than 10 billion messages each day. On August 24, 2014, Koum announced on his Twitter account that WhatsApp had over 600 million active users worldwide. At that point WhatsApp was 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 worldwide users, India has the largest number of consumers.
Facebook acquisition (2014–2015)
On February 19, 2014, months after a venture capital financing round at a $1.5 billion valuation,Facebook announced it was acquiring WhatsApp for US$19 billion, its largest acquisition to date. At the time, the acquisition was the largest purchase of a venture-backed company in history. Sequoia Capital received an approximate 50x return on its initial investment. Facebook, which was advised by Allen & Co, paid $4 billion in cash, $12 billion in Facebook shares, and (advised by Morgan Stanley) an additional $3 billion in restricted stock units granted to WhatsApp's founders, Koum and Acton. Employee stock was scheduled to vest over four years subsequent to closing.Days after the announcement, WhatsApp users experienced a loss of service, leading to anger across social media.
The acquisition caused a considerable number of users to move, or try out other message services as well. Telegram claimed to have seen 8 million additional downloads of its app. 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 internet 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 don’t see the point of why they would pay for those data services. This would give them some context for why they are important, and that will lead them to paying for more services like this – or so the hope goes."

Just three days after announcing that WhatsApp had been purchased by Facebook, Koum said they were working to introduce voice calls in the coming months. He also advanced that new mobile phones would be sold in Germany with the WhatsApp brand, as their main goal was to be in all smartphones.

In August 2014, WhatsApp was the most globally popular messaging app, with more than 600 million active users.[24] By early January 2015, WhatsApp had 700 million monthly active users with over 30 billion messages being sent every day. In April 2015, Forbes predicted that 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 had over 800 million active users. By September 2015, the user base had grown to 900 million, and by February 2016 it had 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 which recognises Telegram URLs has been identified.URLs with "telegram" as domain-name are targeted actively and explicitly – the word "telegram" appears in the code. This functioning risks being considered anti-competitive,and has not been explained by WhatsApp.

Recent (2016-present)
On January 18, 2016, WhatsApp's founder Jan Koum announced that the service would no longer charge their 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][47] He also explained that the app would not 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.
On November 10 2016, WhatsApp has started rolling out two-step verification feature for users on Android beta. This feature will add more security to your account, officials said. After enabling this feature, users will also get an option to add their email address for further protection.Also in November 2016, Facebook ceased collecting WhatsApp data for advertising in Europe.
On February 24 2017, (WhatsApp's 8th birthday) WhatsApp launches new Status feature that offering similar to Snapchat.

Platform support
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 support for Windows Phone 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 phone numbers that connected to WhatsApp using this plug-in.

On January 21, 2015, WhatsApp launched WhatsApp 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 (including BlackBerry 10), Series 40 and Symbian S60, as well as older versions of Android (2.2), Windows Phone (7.0) and iOS , by the end of 2016.BlackBerry, Series 40 and Symbian support was since then extended further to June 30, 2017. In June 2017 support for BlackBerry and Series 40 was once again extended until the end of 2017, while Symbian was dropped.

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 still live on your phone". The WhatsApp user's handset must still be connected to the Internet for the browser application 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 only available 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 developed, which is a standard Win32 application for PCs and supports notifications through the Windows notification area. There are similar solutions for macOS, such as the open-source ChitChat and multiple wrappers available in the App Store.
Windows and Mac

On May 10, 2016, the messaging service was introduced for both Windows and macOS 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 OS X 10.9 and higher.
Technical
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: [phone number]@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 as 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 Dual SIM devices may not be compatible with WhatsApp, though there are some workarounds for this.
In January 2015, WhatsApp introduced a voice calling feature; this helped WhatsApp to attract a completely different segment of the user population. On November 14, 2016, Whatsapp added video calling feature for users across Android, iPhone, and Windows Phone devices.

Multimedia messages are sent by uploading the image, audio or video to be sent to an HTTP server and then 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 WhatsApp server where it is stored. Then the server repeatedly requests the receiver acknowledge receipt of the message. As soon as the message is acknowledged, the server drops the message; it is no longer available in database of server. WhatsApp server keeps the message only for 30 days in its database when it is not delivered (when the receiver is not active on WhatsApp for 30 days).

End-to-end encryption
On November 18, 2014, Open Whisper Systems announced a partnership with WhatsApp to provide end-to-end encryption by incorporating the encryption protocol used in Signal into each WhatsApp client platform.[82] Open Whisper Systems said that they had already incorporated the protocol into the latest WhatsApp client for Android, and that support for other clients, group/media messages, and key verification would be coming soon after. WhatsApp confirmed the partnership to reporters, but there was no announcement or documentation about the encryption feature on the official website, and further requests for comment were declined. In April 2015, German magazine Heise Security used ARP spoofing to confirm that the protocol had been implemented for Android-to-Android messages, and that WhatsApp messages from or to iPhones running iOS were still not end-to-end encrypted.[85] They expressed the concern that regular WhatsApp users still could not tell the difference between end-to-end encrypted messages and regular messages. On April 5, 2016, WhatsApp and Open Whisper Systems announced that they had finished adding end-to-end encryption to "every form of communication" on WhatsApp, and that users could now verify each other's keys. Users were also given the option to enable a trust on first use mechanism in order to be notified if a correspondent's key changes. According to a white paper that was released along with the announcement, WhatsApp messages are encrypted with the Signal Protocol. WhatsApp calls are encrypted with SRTP, and all client-server communications are "layered within a separate encrypted channel". The Signal Protocol library used by WhatsApp is open-source and published under the GPLv3 license.
Cade Metz, writing in Wired, said "WhatsApp, more than any company before it, has taken encryption to the masses."

WhatsApp Payments
WhatsApp Payments is a peer to peer money transfer feature that is set to launch in India. WhatsApp has received permission from the National Payments Corporation of India (NPCI) to enter into partnership with multiple banks in July, 2017 to allow users to make in-app payments and money transfers using the Unified Payments Interface (UPI).UPI enables account-to-account transfers from a mobile app without having any details of the beneficiary's bank.