The app saves a new image and does not overwrite the source image. I have checked this information carefully and can find no price nor any mention of advertisements. I would give more stars but it is rude to spring adverts and requests for money on you without warning you in the information in the App Store. I have given two stars rather than one as it is clear that I had not understood the app properly.
I suspect that I have not understood the app correctly and have uninstalled it.
I made the image larger, the app assured me it was 3000 pixels across (up from 640), but, having saved it and sat through the noisy ad to do so, I found that the original image was unchanged and have been unable to find where the app saved the enlarged image as it is not in files or photos on my tablet and I did not share it anywhere else. I changed the size of an image as an experiment before paying for it. I was not offered a price to buy the ad-free version until I had downloaded the app.
