RSS to instagram user feed is http://widget.websta.me/rss/n/USERNAME
Sergey Redin shared this idea
Done. It’s now possible to subscribe to Instagram accounts, tags and locations.
One more service http://instagrss-mgng.rhcloud.com/USERNAME
I don't understand. Do you want automatic redirects to websta.me feed when users subscribes to instagram?
As I understand websta is a third party service. I don't like the idea of being dependent on third party service.
However I could take a look at Instagram API and try to add direct support.