What systems are you using with an assistant?

[Joseph Cornwell]

For those of you who have one or more assistants for your businesses, what systems are you using to coordinate communication. 

I am looking for my new administrative assistant to be able to be able to access my social media accounts, phone calls, text messages, etc on an Iphone during office hours from my business phone number (which has also been my personal cell number for the past 5 years). Is there a program or software to make this simple, where I could keep my same phone, and she could have a cloned copy? Does apple support this? Is there desktop based programs that would make this possible? I am open to your ideas and any other suggestions, this is my first time learning this process. Thank you!