Pinterest acquired Instapaper back in August and has just announced that it's old paid tier and special features are now free and open to everyone. Many still consider Instapaper to be the gold-standard of read it later apps. It’s a great way to keep track of articles you want to save for later or just read when offline. 

I've used Instapaper for some time and there is some great features built in for organization and research but find myself going back to Pocket allot more.