Messaging apps (a.k.a. "Social messaging" or "chat applications") are apps and platforms that enable messaging, many of which started around social networking platforms, but many of which have now developed into broad platforms enabling status updates, chatbots, payments and conversational commerce (e-commerce via chat).
Some examples of popular messaging apps include WhatsApp, China's WeChat and QQ Messenger, Viber, Line, Snapchat, Korea's KakaoTalk, Google Hangouts, Blackberry Messenger, Signal, Telegram, and Vietnam's Zalo. Slack focuses on messaging and file sharing for work teams. Some social networking services offer messaging services as a component of their overall platform, such as Facebook's Facebook Messenger, along with Instagram and Twitter's direct messaging functions.
Messaging apps are the most widely used smartphone apps with in 2018 over 1.3 billion monthly users of WhatsApp and Facebook Messenger, 980 million monthly active users of WeChat and 843 million monthly active users of QQ Mobile.
In comparison to SMS and instant messaging
Messaging apps differ from the previous generation of instant messaging platforms like the defunct AIM, Yahoo! Messenger, and Windows Live Messenger, in that they are primarily used via mobile apps on smartphones as opposed to personal computers, although some messaging apps offer web-based versions or software for PC operating systems.
As people upgraded in the 2010s from feature phones to smartphones, they moved from traditional calling and SMS (which are paid services) to messaging apps which are free or only incur small data charges. Easier group messaging was another advantage of smartphone messaging apps and also contributed to their adoption.
The United States is notably different from most of the rest of the world – SMS remains popular because it is usually included free in monthly phone bundles, and Apple's iMessage is popular, and uses SMS for messages to non-Apple phones. While SMS volumes in some countries like Denmark, Spain and Singapore dropped up to two-thirds from 2011 to 2013, in the U.S. they only dropped around one quarter.
Before the introduction of messaging apps, smartphone users could only participate in single-person interactions via mobile voice calls or SMS. With the use of SMS and voice calls, group coordination is organized through singular calls/text messages to each individual group member. Although, one person can send the same text message to multiple group members, the group members can't see the responses of everyone else or even know who's in the group at all. Group members only have access to the messages they either send or receive, which hinders group coordination. With the introduction of messaging apps, users can form group chats, where all the members can see an entire thread of everyone's responses. Members can also respond directly to each other, rather than having to go through the member who started the group message, to relay the information. 
Messaging apps each have some of the following features:
- Voice calls
- Video calls
- Audio alerts (on Line)
- File sharing
- "Mini Programs" (e.g. WeChat Mini Program)
- News discovery (e.g. Snapchat Discover)
- Payments or mobile wallet, e.g. WeChat Pay which processes much of the Chinese mobile payment volume of US$5 trillion (2016)
- Personal (cloud) storage
- Push notifications
- Status updates (WhatsApp Status, WeChat Moments)
- Virtual assistant, e.g. Google Assistant in Google Allo
Conversational commerce refers to e-commerce through the use of messaging, whether chatbots or via live (human) agents. In China, WeChat – at its core a messaging app, but also letting merchants display their goods in mobile Web pages and via social feeds – has grown strongly. By 2013 e-commerce in China had overtaken that of the U.S. In 2016, Facebook announced its Facebook Messenger chatbot platform, heralding the arrival of conversational commerce via the most widely used messaging app in the world outside China. More than 34,000 businesses had opened shop on Messenger by August 2017. In September 2017 WhatsApp announced the pilot of its new Enterprise solution – the first time large companies would be able to provide customer service to users via WhatsApp at scale. Among the first companies announcing service on the enterprise platform were airlines KLM and Aeroméxico, Latin American online travel agency Despegar.com and online retailer Linio.
Popularity of Messaging Apps Survey
In 2014, an online survey was distributed via Google Docs to over 52 students at International Islamic University Malaysia. The goal of this survey was to examine the popularity of certain messaging apps, within the demographic of college students. The results showed that WhatsApp was the most installed messaging app in the students' smartphones. Over 98% of the students surveyed, had WhatsApp installed on their smartphones. Telegram (46%), WeChat (35%), Viber (23%), and Line (21%) were some of the other popular choices. 
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