Would there be any method for detecting if an article is available through Blendle when you hit a pay wall article through normal web browsing (eg from a Hacker News link) or I guess this would need to be something the websites implement themselves.
Could be build as a browser extension. Match URL against a list of publications, if the user clicks a button redirect to blendle to check if the specific page is available. (2 stages/manual step to avoid sending every URL you visit to blendle)
We're currently doing experiments integrating with publishers paywalls on their own sites. More here: www.mondaynote.com/2015/10/18/blendles-secret-weapon-its-toolkit-22/
Several Dutch sites have a "read on Blendle" link next to their own signup link on their paywall. It's an extra click, but good enough for me.