This might exist but Googling for it has been a wasteland.

I follow many social media feeds that are other companies in my industry - some partners, some competitors.

I want a script or app or service to dig through their social media history (pics, posts, etc) and send me what's been most engaging.

That's it. Can probably be done in iMacros, just haven't found the time... Could be a small SAAS though.