Tagged photos aren't saved to iPhone – PixSort -- tag and organize your photos Review

I expected this app to save the added tags to the original photos on the iPhone because the app description clearly says that PixSort doesn't make extra copies (which is a desirable feature). But when I view my tagged photos in a different EXIF viewer I can see that the tags were NOT actually saved into the picture on the phone. My guess is that the tags exist as parallel metadata in the PixSort app only and the tags only get added to the picture file through the EXPORT process. Therefore this app is useless to me. I want an app that edits the picture on the iPhone without requiring me to export it in order to get the resulting embedded tags. PixSort, the way it is now, essentially IS CREATING COPIES of the picture by forcing you to export the picture in order to get the edited photo - that is the same unwanted effect as if it directly made copies on your phone itself.
Review by ScottGator on PixSort -- tag and organize your photos.