Can you tag/label photos in iPhone/iOS?
I have been searching for an answer to this for ages but not found anything.
Essentially I want to 'tag/label' my photos within the iPhone iOS' default 'Photos' app so I can use the search function.
I can do this easily on my Macbook; select one or multiple photos, go to the Window/Info or bring up the photo(s) properties and under "Info", add one or more labels to the 'Keywords' area. Then, from any of my Apple devices, I can search my photos using any of those labels/tags i have created and added to my photos.
But i cannot do this labelling from the iPhone itself - only the Macbook through the Photos app. And I have not found an app in iOS which does this exact same labelling in the same way. Some apps mimic this functionality *only* within the app itself (ie: you need to use that app to search photos and doesn't work outside of the app). I want the tags/labels added to the photos in my Apple account so they are searchable across all my Apple devices.
So, does anyone know :
1) How I can do the same tagging/labelling on the iPhone the Macbook can do in Photos?
or
2) Any app which can do this functionality which applies to the Photos across all my Apple devices
(I have seen an Apple article from Oct 2013 which says how to do this on the old iPhoto app which is no longer applicable)
iPhone 6s Plus, iOS 9.1