In the application I am developing, I'd like to refer to people who have had something shared with them (link, photo etc.) but I couldn't figure out what word or phrase to use.
Recipient: receiver: somebody or something that receives something.
It sounds a little awkward and perhaps corny, but you could try sharee. (The person who initiates the sharing is the sharer.)
In this case I would describe that person as a recipient or a receiver.
According to Oxford Dictionaries, a receiver is:
A person who gets or accepts something that has been sent or given to them.
You could also simply use a phrase "the person/people you shared with".
I usually use words like group, network, or team when conveying these things on apps. Might say your photo group, target network, entrusted network... It really depends on what your app is doing and what atmosphere it will be used in.
a person who gains or benefits in some way from something