The Living Hope Ministries programme for mobile phones and tablets seeks to support those seeking help for unwanted feelings.
While it's been available for several years, it's recently come under criticism with some claiming it to be homophobic.
One article on the app suggests finding a counsellor who has a "biblical understanding that homosexuality is changeable through the power of Jesus Christ".
"The views contained in this app have the potential to cause huge damage to LGBT people who might come across it," said Laura Russell, head of policy at UK LGBT equality charity Stonewall.
"Any form of 'therapy' that attempts to change someone's sexual orientation or gender identity is unethical and wrong.
"These so-called 'therapies' have been condemned by all major UK health organisations as they try to shame a person into denying a core part of who they are, and this can have a seriously harmful impact on their mental health and wellbeing.
"We urge Google to take swift action to remove content advertising the practice."
Apple, Microsoft and Amazon have already made the app unavailable on their platforms.
"It is unconscionable that Google is still offering an online platform to an organisation that seeks to marginalise and stigmatise LGBT people," said Wayne Besen, executive director of Truth Wins Outs, which aims to tackle anti-gay religious extremism.
"It's time for Google to join Apple, Microsoft and Amazon to delete this hateful and dangerous app that promotes prejudice and fosters discrimination."
A petition calling for a ban on the app has received over 38,000 signatures.
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