Messenger

Messenger Kids is a messaging app and platform released by Facebook, Inc. (now Meta Platforms) in December 2017. The platform is designed for a young audience as a safer alternative to the Messenger platform. Users can register with their first and last names instead of phone numbers. It was initially launched for iPad tablets with the iOS operating system in the United States only, though later support for iPhone and Android devices was added and it was rolled out in Canada, Peru, and Mexico.

Parents have oversight and control, with requirements about identity verification and approval of contacts. There are no in-app purchases nor advertisements, and thus also no data collection for advertising purposes, children's accounts are not visible in search on Facebook, and the child's account does not automatically migrate to a full Facebook account once the child turns 13 years old (the minimum age for Facebook registration). It features augmented reality filters and lenses, along with games and educational content.

WhatsApp Messenger, or simply WhatsApp, is an American freeware, cross-platform centralized instant messaging (IM) and voice-over-IP (VoIP) service owned by Meta Platforms. It allows users to send text messages and voice messages, make voice and video calls, and share images, documents, user locations, and other content. WhatsApp's client application runs on mobile devices but is also accessible from desktop computers, as long as the user's mobile device remains connected to the Internet while they use the desktop app. The service requires a cellular mobile telephone number to sign up.

Telegram is a freeware, cross-platform, cloud-based instant messaging (IM) system. The service also provides end-to-end encrypted video calling, VoIP, file sharing and several other features. It was launched for iOS on 14 August 2013 and Android in October 2013. The servers of Telegram are distributed worldwide to decrease frequent data load with five data centers in different regions, while the operational center is based in Dubai in the United Arab Emirates. Various client apps are available for desktop and mobile platforms including official apps for Android, iOS, Windows, macOS and Linux (although registration requires an iOS or Android device and a working phone number). There are also two official Telegram web twin apps – WebK and WebZ – and numerous unofficial clients that make use of Telegram's protocol. All of Telegram's official components are open source, with the exception of the server which is closed-sourced and proprietary.

Telegram provides end-to-end encrypted voice and video calls and optional end-to-end encrypted "secret" chats. Cloud chats and groups are encrypted between the app and the server, so that ISPs and other third-parties on the network can't access data, but the Telegram server can. Users can send text and voice messages, make voice and video calls, and share an unlimited number of images, documents (2 GB per file), user locations, animated stickers, contacts, and audio files. In January 2021, Telegram surpassed 500 million monthly active users. It was the most downloaded app worldwide in January 2021 with 1 billion downloads globally as of late August 2021.

Snapchat is an American multimedia messaging app developed by Snap Inc., originally Snapchat Inc. One of the principal features of Snapchat is that pictures and messages are usually only available for a short time before they become inaccessible to their recipients. The app has evolved from originally focusing on person-to-person photo sharing to presently featuring users' "Stories" of 24 hours of chronological content, along with "Discover," letting brands show ad-supported short-form content. It also allows users to keep photos in the "my eyes only" which lets them keep their photos in a password-protected space.

Snapchat was created by Evan Spiegel, Bobby Murphy, and Reggie Brown, former students at Stanford University. As of March 2020, Snapchat had 229 million daily active users. On average more than 4 billion Snaps are sent each day. Snapchat is known to be popular among the younger generations, particularly those below the age of 16, leading to many privacy concerns for parents.

Facebook is an American online social media and social networking service owned by Meta Platforms. Founded in 2004 by Mark Zuckerberg with fellow Harvard College students and roommates Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes, its name comes from the face book directories often given to American university students. 

Facebook can be accessed from devices with Internet connectivity, such as personal computers, tablets and smartphones. After registering, users can create a profile revealing information about themselves. They can post text, photos and multimedia which is shared with any other users that have agreed to be their "friend", or, with a different privacy setting, with any reader. Users can also use various embedded apps, join common-interest groups, buy and sell items or services on Marketplace, and receive notifications of their Facebook friends' activities and activities of Facebook pages they follow. Facebook claimed that it had 2.80 billion monthly active users as of December 2020, and it was the most downloaded mobile app of the 2010s globally.

Instagram (commonly abbreviated to IG or Insta) is an American photo and video sharing social networking service owned by Facebook, created by Kevin Systrom and Mike Krieger and originally launched on iOS in October 2010. The Android version was released in April 2012, followed by a feature-limited desktop interface in November 2012, a Fire OS app in June 2014, and an app for Windows 10 in October 2016. The app allows users to upload media that can be edited with filters and organized by hashtags and geographical tagging. Posts can be shared publicly or with pre-approved followers. Users can browse other users' content by tags and locations and view trending content. Users can like photos and follow other users to add their content to a feed, a function that seems to be discontinued as of September 2020.

Instagram was originally distinguished by only allowing content to be framed in a square (1:1) aspect ratio with 640 pixels to match the display width of the iPhone at the time. In 2015, these restrictions were eased with an increase to 1080 pixels. The service also added messaging features, the ability to include multiple images or videos in a single post, and a Stories feature—similar to its main opposition Snapchat—which allows users to post photos and videos to a sequential feed, with each post accessible by others for 24 hours each. As of January 2019, the Stories feature is used by 500 million users daily.

After its launch in 2010, Instagram rapidly gained popularity, with one million registered users in two months, 10 million in a year, and 1 billion as of June 2018. In April 2012, Facebook acquired the service for approximately US$1 billion in cash and stock. As of October 2015, over 40 billion photos had been uploaded. Although praised for its influence, Instagram has been the subject of criticism, most notably for policy and interface changes, allegations of censorship, and illegal or improper content uploaded by users.

As of January 2021, the most followed person is footballer Cristiano Ronaldo with over 253 millionfollowers. As of January 14, 2019, the most-liked photo on Instagram is a picture of an egg, posted by the account @world_record_egg, created with the sole purpose of surpassing the previous record of 18 million likes on a Kylie Jenner post. The picture currently has over 54 million likes. Instagram became the 4th most downloaded mobile app of the 2010s.

Discord is an American VoIP, instant messaging and digital distribution platform designed for creating communities. Users communicate with voice calls, video calls, text messaging, media and files in private chats or as part of communities called "servers." 

Servers are a collection of persistent chat rooms and voice chat channels. Discord runs on Windows, macOS, Android, iOS, iPadOS, Linux, and in web browsers. As of 2021, the service has over 350 million registered users and over 150 million monthly active users.

Skype Technologies S.A.R.L (also known as Skype Software S.A.R.L, Skype Communications S.A.R.L, Skype Inc., and Skype Limited) is a Luxembourger telecommunications company headquartered in Luxembourg City, Luxembourg, whose chief business is the manufacturing and marketing of the video chat and instant messaging computer software program Skype, and various Internet telephony services associated with it. Microsoft purchased the company in 2011, and it has since then operated as their wholly owned subsidiary; as of 2016, it is operating as part of Microsoft's Office Product Group. 
Skype, a voice over IP (VoIP) service, was first released in 2003 as a way to make free computer-to-computer calls, or reduced-rate calls from a computer to telephones. Support for paid services such as calling landline/mobile phones from Skype (formerly called SkypeOut), allowing landline/mobile phones to call Skype (formerly called SkypeIn and now Skype Number), and voice messaging generates the majority of Skype's revenue.

Zoom Meetings (commonly shortened to Zoom, and stylized as zoom) is a proprietary video teleconferencing software program developed by Zoom Video Communications. The free plan allows up to 100 concurrent participants, with a 40-minute time restriction. Users have the option to upgrade by subscribing to a paid plan. The highest plan supports up to 1,000 concurrent participants for meetings lasting up to 30 hours.

During the COVID-19 pandemic, there was a major increase in the use of Zoom for remote work, distance education, and online social relations. The increase led to Zoom being the 5th most downloaded mobile app worldwide in 2020 at 477 million downloads.