You can use any messaging app (even sms or email) if you want to share something to only a limited number of people. And it would be private with no verification needed.
In order to see content from a private Instagram account, you just need to use the instagram private viewer. I really like this site because here you can easily follow a closed account and find out all the information you need. In fact, this is very funny because the person does not even know that you visited his page. Hope you enjoy this website.