Is there a way to automate sharing to various social media platforms at once?

I am looking for a way to share to various social media accounts (such as Twitter, Instagram, and Facebook) with one click of a button. I have found various automating/scheduling tools for social media like Later, Buffer, etc that allow for this sharing, but I am interested in trying to build this feature into my own app without the use of a third party tool. Does anyone have any tips or ideas on how to do this?