Twitter

Twitter is a messaging service and app that is available for iOS, iPadOS, tvOS, Android, and web browsers. The iOS app was launched in October 2009.

Features
Registered users are allowed to send and receive short posts called "tweets", which can be up to 280 characters long (formerly 140) and can include links to relevant websites and resources.

Twitter users can follow other accounts of people and organizations. Such an account will be accompanied by a blue checkmark if the identity has been verified by Twitter. Tweets from a "followed" account will automatically appear in a follower's "timeline". An account's pattern of following and usage will result in the of tweets and events from people and organizations with similar academic and personal interests to the user. Twitter states that its curation team is not responsible for driving revenue, user growth, or relationships with its partners.

Twitter announced in June 2018 that it was investing in and  detection, to prevent "",, hateful conduct, and violent extremism. In 2019, the company was removing over 6 to 7.5 million "fake" accounts per week.

iOS and macOS apps
In April 2010, Twitter announced it had acquired the iPhone app Tweetie and rebranded it as "Twitter for iPhone". The developer of Tweetie,, became part of Twitter's mobile division and helped launch the "Twitter for iPad" application.

On January 6, 2011, Twitter announced that the company had also acquired the desktop version of Tweetie, changing the name to "Twitter for Mac". Twitter for Mac was launched on the new Mac App Store the same day. On Tuesday, May 21, 2013, Twitter announced that certain patents related to Tweetie would only be used to defend Twitter. Ultimately, Twitter for Mac was discontinued in March 2018 after a very slow maintenance schedule. In October 2019, the macOS client was replaced by the iPadOS version, which had been converted through Catalyst.

Company history
Twitter was co-founded by, , , and in 2006. Dorsey served as CEO from 2006 to 2008, and again from 2015 until resigning in November 2021, stating his "regret" for Twitter's role in the centralization of internet usage. On March 14, 2022, CEO  acquired a 9.2% stake in Twitter, making him the single largest shareholder. Musk had expressed his disappointment in current CEO, who had succeeded Dorsey. On April 25, 2022, Twitter accepted Musk's offer to buy the remainder of the company outright in exchange for $44 billion. However, Musk placed the deal on hold pending an audit of how many users on Twitter are actually spam or fake accounts. The deal finally closed on October 27, 2022, averting a potential lawsuit.

Change of ownership
Upon becoming the company's new owner, Musk immediately fired the senior management and dissolved the board of directors. Twitter then began offering its trademark blue verification checkmarks for 8, causing advertisers to leave the platform over concerns of the potential for spoofing. The checkmark program was quickly suspended after Twitter was flooded with a wave of fake accounts. Within weeks, the majority of the staff and been fired or exited the company after rejecting Musk's demand that workers put in long "extremely hardcore" hours. By November 17, Musk was scrambling to convince remaining staff to stay. With minimal staff remaining, Musk ordered microservices turned off, calling it "bloatware". However, users then found that Twitter's system stopped working, causing them to be locked out of their accounts. Worried about the potential for sabotage to the company, Musk ordered the company headquarters in San Francisco temporarily closed.

On November 19, 2022, Musk reinstated the banned account of former U.S. president Donald Trump after a quick poll and then invited him to return with a misogynistic meme, which was described by critics as "desperate". However, Trump responded by stating that he had no interest in returning to Twitter and would stay at Truth Social.

On November 30, 2022, Musk met with Apple CEO Tim Cook at Apple Park after claiming in a tweet that Apple had threatened to pull the Twitter app from the App Store. Musk later deleted the tweet and instead stated, "Tim was clear that Apple never considered doing so." Musk added that Apple had "fully resumed advertising", even after much of the ad business staff had been cut. Musk also deleted a meme criticizing Apple's App Store fees and stated that Twitter would reprice its blue checkmark subscription fee to $7 through the Twitter website and $11 through mobile apps, to offset App Store fees.

System requirements
Twitter is also supported by major web browsers that have received security updates within the previous year.
 * iOS 14 or later
 * iPadOS 14 or later
 * macOS 11 or later
 * tvOS 10 or later