Apple appears to have pulled an iPhone and iPad app promising "freedom from homosexuality through the power of Jesus" after coming under fire from gay rights activists.

More than 146,000 people signed a petition calling on Apple to remove the so-called "gay cure" app backed by Exodus International, a Christian group that describes itself as "the world's largest worldwide ministry to those struggling with unwanted same-sex attraction".

According to the Florida-based group, homosexuality is "a multicausal, developmental issue and that any individual can experience freedom through the support of caring individuals and the healing power of Jesus Christ". The app aims to give users "a useful resource for men, women, parents, students and ministry leaders" to "reconcile their faith with their sexual behaviour".

The app has been on sale since 15 February but was last night no longer available. Apple has yet to comment on the furore that the app sparked and was unavailable for comment. The company has strict rules on governing the content of apps and regularly blocks apps it believes may cause offence or contain risqué content. Exodus had been marked "4+" by the company, a grade that meant Apple judged it contained no objectionable content.

In the petition letter addressed to Steve Jobs, the Apple chief executive, and posted last week on the Change.org site, objectors said: "Apple doesn't allow racist or anti-semitic apps in its app store, yet it gives the green light to an app targeting vulnerable LGBT youth with the message that their sexual orientation is a 'sin that will make your heart sick' and a 'counterfeit'.

"This is a double standard that has the potential for devastating consequences. Apple needs to be told, loud and clear, that this is unacceptable."

The objectors called on people to continue signing the petition last night. Noting that the app no longer appears to be available, they wrote: "Does that means Apple has pulled the app, like more than 140,000 customers have asked? It's hard to tell; Apple hasn't issued an official statement yet. Until they do, it's important that we keep up the pressure, so that Apple hears loud and clear that "ex-gay" therapy deserve no place in the App Store."

Earlier this week Dr Gary Remafedi, director of the Youth and AIDS Projects, accused Exodus of distorting his research into homosexuality and called on Apple to remove the app. In a letter to Apple Remafedi, director of the youth and Aids projects and a professor of pediatrics at the University of Minnesota, said the app "erroneously cites my research in support of claims that homosexuality can be changed ... Associating my work with that of the ex-gay ministry and other unfounded treatments is professionally injurious and grievous."

He told the Minneapolis-St Paul Star Tribune that he had challenged many misrepresentations of his work over the years and has had "100%" success in doing so. Apple had responded to his letter. "They said they are on it," Remafedi said. "I am simply pointing out a problem. I'm sure they will do the right thing."