Why has Parler gained popularity?
Parler calls itself as "unbiased" social media and has been popular among people who are banned from Twitter. But Google said the app had failed to remove posts inciting violence.
In fact, Apple has also warned the social media platform that it will remove the app from its store if it does not comply with its content-moderation requirements.
On Parler, the app's chief executive John Matze said: "We won't cave to politically motivated companies and those authoritarians who hate free speech!"
Launched in 2018, Parler has been able to garner users particularly among supporters of US President Donald Trump and right-wing conservatives. Such groups have frequently criticised Twitter and Facebook for unfairly censoring their views.
Who are high profile Parler users?
Although Trump is not on the platform, Parler already features several high-profile contributors following earlier bursts of growth in 2020.
Texas Senator Ted Cruz boasts 4.9 million followers on the platform, while Fox News host Sean Hannity has about seven million. It briefly became the most-downloaded app in the United States after the US election, following a clampdown on the spread of election misinformation by Twitter and Facebook.
However, both Apple and Google have said the app fails to comply with content-moderation requirements.