Tweak it, doesn't have to be a major change and resubmit with information about what it does that a native app can't in the review notes (tracking sent images).

Tweak it, doesn't have to be a major change and resubmit with information about what it does that a native app can't in the review notes (tracking sent images). If that doesn't work maybe add basic image editing options (cropping etc.) or think about whether there are useful offline features you could add. Note that I don't have much experience with rejections but that is what I would do.