China's growing importance in the technology world is a double-edged sword for U.S. brands. As controversies involving Apple and Activision Blizzard have shown of late, the opportunity to play in the country's mammoth consumer market can also land companies in hot water around the globe. Issues like the Chinese government's clash with pro-democracy protesters in Hong Kong are particularly sensitive, drawing accusations that companies put profits ahead of principles like free speech.

Following are eight apps and video games that have recently come under the spotlight because of Chinese involvement, from issues related to censorship to data privacy concerns.

HKmap.live

Apple last week removed a smartphone app from its online store after an official Chinese newspaper accused the company of facilitating "illegal behavior" in Hong Kong. HKmap.live, which tracks police movements, prompted the Communist Party newspaper People's Daily to ask: "Is Apple guiding Hong Kong thugs?"

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HKmap.live's developers said Apple's decision to remove the app deliberately suppresses freedom and human rights. But Apple said the app violated local laws, as well as Apple's own company guidelines.

Apple has deep business ties in China where it manufactures just about all of its iPhone, iPad and Mac devices. But the Cupertino, California-based company also depends on the massive Chinese consumer market for nearly one-fifth of its revenue. Last year, China alone generated $52 billion out of $266 billion total global sales for the tech giant.

Apple chief executive Tim Cook has also said China eventually will become the No. 1 market for the company.

Revolution of our Times

Google pulled a mobile game from its online store that allowed Android users to role-play as Hong Kong protesters. According to the Hong Kong Free Press, 80% of the proceeds from the app Revolution of Our Times goes to Spark Alliance, the legal fund for arrested protesters.

Unlike Apple, Google is not as deeply entrenched in the Communist state, famously pulling its services like Gmail and Youtube from China in 2010. Last year, the Asian-Pacific region accounted for about $21 billion of Google-parent Alphabet's roughly $137 billion in global sales.

Study the Great Nation

The most popular app to launch in China this year is probably one you've never heard of before. Study the Great Nation reportedly has been downloaded 100 million times since it launched in January, according to a recent report from German cybersecurity firm Cure 53. The firm also found that the app, developed by Chinese technology giant Alibaba and the government's propaganda department, has a back door essentially giving developers "superuser" access to smartphones.

The app is used by Chinese state officials and in many of the nation's workplaces, the Washington Post reported. That has drawn comparisons to Mao's "Little Red Book," which encouraged the study of Communist principles for party members.

Hearthstone, Overwatch and World of Warcraft

Last week, American video game company Activision Blizzard caused an outcry after its subsidiary Blizzard Entertainment punished a star Hong Kong gamer for making pro-democracy remarks in an interview following a Hearthstone tournament. The online gaming community called for boycotts of Blizzard, with critics accusing the company of putting its business ties with China over free speech values. Chinese technology giant Tencent has a near 5% stake in Activision Blizzard.

Activision Blizzard has three subsidiaries — Activision Publishing, Blizzard Entertainment and King Digital Entertainment — that are responsible for some of the world's most popular video game titles, like Call of Duty and Candy Crush. At the time of the Hong Kong player's remarks, Blizzard has been bleeding sales, but Activision was seeking Chinese approval for its top money-making game Call of Duty.

The video game market is massive in China. It is projected to generate $36.5 billion in revenue this year, just behind the U.S. at $36.9 billion, according to esports analytics firm Newzoo.

League of Legends

The online battle arena game League of Legends was developed by esports company Riot Games, which is entirely owned by Chinese technology giant Tencent. After the Blizzard controversy, the West Los Angeles, California-based esports company last week urged its sportscasters and players to steer clear of "sensitive topics" during a high-profile tournament.

"These topics are often incredibly nuanced, require deep understanding and a willingness to listen, and cannot be fairly represented in the forum our broadcast provides," John Needham, global head of League of Legends Esports, said in a statement on the League of Legends official Twitter account.

Fortnite

Tencent also has a 48% stake in Epic Games, which created the enormously popular video game Fortnite. Referencing Blizzard's move to sanction a gamer for speaking out on the Hong Kong protests, Epic Games chief executive Tim Sweeney tweeted last week that the company will never punish players' political speech.

"That will never happen on my watch as the founder, CEO and controlling shareholder," Sweeney wrote.

TikTok

China's popular teen app, TikTok, launched in the U.S. just over a year ago, but it has already surged to the top of the app store. Its parent company, ByteDance, is now the most highly valued startup in the world, with a valuation of $75 billion.

Now, the first Chinese social-media app to gain traction in the U.S. is coming under increased scrutiny from lawmakers concerned about its history of data privacy scandals and its information practices. Last month, a Washington Post report found that TikTok appeared to be censoring the Hong Kong protests on its platform — a search on the platform yielded few results compared with what searches turned up on Twitter or Instagram.

Republican Senator Marco Rubio earlier this month called for the Committee on Foreign Investment in the United States, or CFIUS, to investigate TikTok's 2017 merger with Musical.ly. "Ample & growing evidence exists that TikTok's platform for western markets, including the U.S., are censoring content in line with #China's communist government directives," Rubio wrote.

Grindr

In March, CFIUS also flagged American gay dating app Grindr as a national security risk and demanded that its Chinese owner, Beijing Kunlun Tech, sell the platform, which it did in May.

Grindr doesn't collect different user data than other social networking apps, but experts said the decision stemmed from growing concerns about Chinese espionage and data privacy. The company, which had 27 million users on its platform as of 2017, last year was discovered to have shared users' HIV status and sexual preferences with third parties. It also tracks email addresses, passwords, billing information, geolocations, as well as messages exchanged with other users and photographs.

Tech experts said that could make it a goldmine for blackmailers looking to identify government and military personnel, who could be pressured to reveal state secrets if they shared sensitive information on the app.