The app has been at the centre of a viral phenomenon over recent days, as celebrities and normal people rush to change their pictures to find out how they would look if they were old, young, or a different genre.
But it has also been hit by privacy questions as users wonder what is happening to those photos when they are edited.
They argue that the company takes a cavalier approach to users' data - but FaceApp said in a statement most images were deleted from its servers within 48 hours of being uploaded.
First, it said that it does need to upload images to the cloud so that they can be edited on its servers. But it stressed that it only uploads the single photo that is chosen by users, and that other images are not taken off a person's device. That runs contrary to a host of viral tweets and posts, which have suggested that the app hoovers up every image on a person's phone when it is opened.
Third-party security experts had already suggested this isn't the case, and iPhones have protections in place that stop an app even seeing a user's images unless permission is given.
If users want to remove data manually, then it is possible to submit a request, FaceApp said.
https://www.independent.co.uk/life-style/gadgets-and-tech/news/faceapp-privacy-concerns-response-questions-viral-photo-app-challenge-download-a9008911.html
https://www.bbc.co.uk/news/technology-49018103
https://news.sky.com/story/are-celebrities-putting-themselves-at-risk-by-using-faceapp-11765485