Since Google Reader shut down, I’ve used Feedbin as my reader of choice. Reeder for iPhone supports it and so does Mr. Reader for iPad. The web interface recently got an update and one of the more interesting features is the support for URL sharing.
By going to Github and entering the URL scheme for your favorite social sharing service, you can customize how you share. I mostly use Buffer to schedule my posts but if I want to share directly, I can – if native Mac or iOS apps support URL callbacks, you can use them, too.