It's a good job that painters down the ages haven't been called to task over the integrity and accuracy of their depictions of historical and mythical (including Biblical) scenes, eh?
Years ago, people used to say "the camera never lies" and that's true insofar as the camera does no more and no less than what you tell it to do. When it comes to image manipulation, all digital photography and apps like Photoshop have done is magnified the extent and ease with which the changes can be made. How far you push those changes and the rights and wrongs are subjective and I don't believe anyone is unfailingly right or wrong.
It really disappoints me that, In the 21st century, we still allow ourselves to take any notice of apps that tell us what's good, bad or indifferent. Are we that stupid and lazy? For me, it's a bit like "Britain's Got Talent", "The X Factor" and "The Voice", etc. I can only speak for myself but I really don't need some pillock like Simon Cowell (to name but one) to tell me whether the act who's just done their thing (whatever that may be) has any talent or whether I should/shouldn't like them. Moreover, why the hell would I want to pay for the privilege by voting for them or buying some piece of geekery to tell me this photo is "better" than that photo?
We really do need to start thinking for ourselves again.