What's up with apps?
Apps evolve - generally but not always for the better. Early apps were pretty simple but as new versions come out, they frequently include more features. Since the camera app in early iPhones just took pictures, I installed numerous apps - sometimes to replace the iPhone version but often to do "post processing" - adjusting brightness, contrast, cropping, etc.
In addition to taking still pictures and videos the current iPhone camera takes time lapse, slow motion, square and panorama pics. It also includes burst mode, HDR and shutter delay as well as a variety of editing tools and numerous export options. Just as specialty programs that once supplemented Microsoft Word, disappeared as their capabilities were rolled into Word, these specialty apps will fade away. Frequently these apps do a better job with these extra features but often "good enough" is - well - good enough!
We can just hope that app developers don't cram so much into their new versions that they become unwieldily - the fate of many PC apps over the years.